55162 Federal Register / Vol. 59, No. 212 / Thursday November 3, 1994 / Rules and Regulations

DEPARTMENT OF TRANSPORTATION

Research and Special ProgramsAdministration

49 CFR Parts 171, 173, 178, and 180[Docket No. HM-183C; Amdt. Nos. 171-129,173-240, 178-105, 180-7]

RIN 2137-AC37

Cargo Tanks; MiscellaneousRequirements

AGENCY- Research and Special ProgramsAdministration (RSPA), DOTACTION: Final rule.

SUMMARY- RSPA is amending certainrequirements for the manufacture,qualification and maintenance of cargotank motor vehicles. These regulatoryactions are based on petitions forrulemaking, exemptions, NationalTransportation Safety Boardrecommendations, and RSPA initiative.The intended effect of these actions isto relax certain regulatory requirementsand to reduce unnecessary economicburdens on industry where there will beno adverse effect on safety.DATES: Effective date: January 5, 1995.

Compliance date: Compliance withthe regulations, as amended herein, isauthorized immediately.

Incorporation by reference: Theincorporation by reference of certainpublications listed in this final rule isapproved by the Director of the Officeof the Federal Register as of January 5,1995.FOR FURTHER INFORMATION CONTACT:Ronald Kirkpatrick, telephone (202)366-4545, Office of Hazardous MaterialsTechnology or Jennifer Karim, (202)366-4488, Office of Hazardous MaterialsStandards, Research and SpecialPrograms Administration, U.S.Department of Transportation,Washington, DC 20590-0001.

SUPPLEMENTARY INFORMATION:

I. BackgroundOn March 3, 1993, RSPA published in

the Federal Register a notice ofproposed rulemaking (NPRM) [DocketNo. HM-183C, Notice No. 93-7" 58 FR12316] proposing to amend certainrequirements for the manufacture,qualification and maintenance of cargotank motor vehicles. Most issues raisedin the NPRM relate to requirements thatwere adopted in final rules publishedunder Docket No. HM-183/HM-183A(June 12, 1989, 54 FR 24982; May 22,1990, 55 FR 21035; September 7 1990,55 FR 37028; June 17 1991, 56 FR27872). The final rules established threenew cargo tank specifications

designated as DOT 406, DOT 407 andDOT 412, and revised the structuraldesign requirements for MC 331 and MC338 cargo tanks. Voluntary ,compliancefor manufacture of cargo tanks to thesenew or revised specifications wasauthorized beginning on October 1,1990.

As manufacturers began modifyingtheir manufacturing operations toconstruct cargo tanks to the newrequirements, they encountered certaintechnical, problems which caused themto question changes they had endorsedseveral years ago. They raised issuesrelating to structural integrity, accidentdamage protection, use of dual functionpressure relief devices, and certificationby the American Society of MechanicalEngineers (ASME). Also RSPA receivedseveral petitions for rulemakingaddressing certain issues not previouslyraised. In the NPRM, RSPA pointed outthese concerns and other issues basedon petitions for rulemaking,exemptions, and NationalTransportation Safety Board (NTSB)recommendations. The NPRM alsoannounced a public meeting that washeld in Chicago on March 24 and 25,1993, to address issues raised in theNPRM.

On March 8, 1993, RSPA published afinal rule [Docket HM-183, 58 FR12904] granting an extension until April21, 1994, for the continued constructionof cargo tank motor vehicles to the MC306, MC 307 MC 312, MC 331, and MC338 specifications. This action wasgranted to allow additional timeforRSPA and industry to address certaintechnical issues concerning themanufacture of cargo tank motorvehicles to the DOT 406, DOT 407 andDOT 412 specifications, and to resolvecertain concerns about the -structuraldesign requirements in the MC 331 andMC 338 specifications.

At the March 24-25 public meeting,several significantly different views ofdesign engineers and cargo tankmanufacturers were identified.Additionally preliminary results werepresented of an advanced structuralevaluation (using finite elementanalysis) of the MC 331 cargo tankwhich raised questions in regard tostress levels in areas of concentratedloadings.

On January 12, 1994, RSPA publisheda final rule [Docket HM-183, 58 FR1784] granting another extension untilAugust 31, 1995, for continuedconstruction of cargo tank motorvehicles to the MC specifications. Thefinal rule also announced a publicmeeting in Washington, D.C. onFebruary 7-8, 1994.

At the February public meeting, RSPAobtained clarification of certaincomments received in response to theNPRM and also obtained additionalsupporting data on certain alternateproposals offered by industry. Inaddition, RSPA sought information toresolve the remaining issues onstructural integrity, accident damageprotection, use of dual function pressurerelief devices, and ASME certification oflow pressure cargo tank motor vehiclemanufacturers.

I1. Summary of CommentsRSPA received over 50 written

comments in response to the proposalscontained in the NPRM from tradeassociations, cargo tank manufacturersand repairers, manufacturers of cargotank parts and equipment, and Federal,State and local agencies. RSPA hasconsidered all comments, publicmeeting transcripts and petitions in thedevelopment of this final rule.

In the NPRM, RSPA informedindustry that the following items wouldbe open for discussion at the Marchpublic meeting:

1. Application of the ASME Code toDOT 400-series specification cargo tankmotor vehicles.

a. The feasibility of citing all sectionsof the ASME Code that must be met inconstruction of DOT specification cargotank motor vehicles as opposed to citingonly those sections that do not apply.

b. The development of a consensusstandard containing procedures forquality control, welding and design asan alternative to the procedurescontained in the ASME Code.

2. The progress of the industry ondevelopment and testing of dualfunction vents, reclosing pressure reliefdevices capable of reseating with theloss of less than one gallon of lading,and self-closing systems for vacuum-loaded hazardous waste tanks.

3. The regulatory proposals containedin the NPRM.

Most commenters supportedapplication of the ASME Code. Onecommenter stated that his company-which had initially opposed becomingASME certified, has benefited from theexpertise of the National Boardinspector.

The ASME Code is an internationallyrecognized consensus standard for thedesign and construction of pressurevessels. It is also the only proven qualitycontrol standard for pressure vesselsand cargo tanks.

The Cargo Tank ManufacturingAssociation (CTMA) submitted a draftquality control manual for review.CTMA recommended that RSPArecognize the manual, which includes

Federal Register / Vol. 59, No. 212 / Thursday, November 3, 1994 / Rules and Regulations 55163

quality control procedures, as analternative to requiring manufacturers tohave an ASME "U" stamp or NationalBoard "R" stamp. The use of thealternative standard recommended byCTMA is not equivalent in scope anddetail to the ASME Code and is notincluded in this final rule.

It has also oeen brought to RSPA'sattention that some "U" stamp and "R"stamp holders may believe they are notrequired to apply all provisions of theASME or National Board quality controlprogram for work on non-ASME DOTspecification cargo tanks. When theregulations requiring cargo tankmanufacturers and repair facilities tohold "U" and "R" stamps werepromulgated, RSPA stated in thepreamble discussions of the final rulesand at public meetings that majorprovisions of the ASME or NationalBoard quality control programs wouldapply to all work on DOT specificationcargo tanks. Such provisions includewelder qualifications, weldingtechmques, and quality controlprocedures. For instance, refer to thepreamble discussions in the followingfinal rules: "B. Cargo Tank:Manufacturer Qualification,Registration, Quality Control, andCertification," (June 12, 1989, 54 FR24984); "Section 180.413 (Repair,Modification, Stretching, andRebarrelling)," (September 7 1990, 55FR 37044).

One commenter stated that specifyingall applicable sections of the ASMECode, rather than providing exceptionsto sections that are not applicable,would provide greater assurance toengineers and designers that they havenot overlooked an obscure section of theASME Code. The commenter did notprovide RSPA with any suggestedwording for implementation of therecommendation.

The National Propane Gas Association(NPGA) submitted a report on thestructural integrity of the MC 331specification cargo tank. NPGArecommended uniformity in designloading requirements for all DOTspecification cargo tanks. RSPA willconsider the design loadingrequirements for MC 331 and MC 338specification cargo tanks in a futurerulemakmg. The report is available forreview in the public docket

in. Section-by-Section Review

This review by section discusses onlysignificant comments received to theproposals in the NPRM, changes madebased on alternative proposals offeredby commenters, and clarifications tocertain provisions based on RSPA'sinitiatives. For those provisions that are

adopted as proposed, readers arereferred to the preamble discussion inthe NPRM,

Section 171.7The Truck Trailet Manufacturers

Association (TTMA) submitted apetition for rulemaking (P-1236)requesting RSPA to incorporate byreference the latest editions of theASME Code from the 1986 Edition andAddenda through 1985 to the 1992edition and Addenda through 1993, andto update the National Board inspectionCode from the 1983 Edition to the 1992Edition. RSPA has reviewed theseupdated standards and agrees the latesteditions should be referenced. The tablein paragraph (a)(3) has been revisedaccordingly.

Section 173.33Consistent with changes made in

§ 180.405(h) in this final rule, a newsentence is added to paragraph (d)stating that the venting requirements ofthe original DOT cargo tankspecification mustbe met whenever apressure relief valve is modified to amore recent specification. See preamblediscussion for S 180.405(h). Similarly inview of changes made in §§ 178.337-11and 178.338-11 in this final rule, a newparagraph (h) is added to informshippers that certain MC 331 and MC338 cargo tanks manufactured afterAugust 31, 1995, must have remotelycontrolled, internal, self-closing stopvalves. See preamble discussion for§ 178.337-11.

Section 173.225Commenters supported the proposal

to revise paragraph (e)(2) to authorizethe use of MC 307 and DOT 407 cargotank motor vehicles for certain organicperoxides. However, one commenteropposed allowing the use of MC 307cargo tanks for all organic peroxides.This commenter misunderstood theproposal. Note 14 to the § 173.225(b)Table authorizes bulk packagings foronly a few organic peroxides. Therefore,paragraph (e)(2) is adopted as proposedin the NPRIv

Section 173.315For cargo tank motor vehicles in

chlorine service, changes inrequirements for hose, piping or tubingto be carried on the vehicle and inrequirements for testing angle valves, asproposed mn the NPRM, are adopted asparagraphs (o)(1) and (o)[2) respectively.

Section 178.337-1Paragraphs'(a)(3) and (e)(1) are revised

to correct certain section references andparagraph(e)(2) is revised to authorize

the use of ceramic fiber/fiberglassinsulation for cargo tanks in chlorineservice as proposed in the NPRM.

Section 178.337-9

As proposed in the NPRM, therestriction is removed against mountingor carrying on a cargo tank motorvehicle any hose, piping or tubin7 usedin loading or unloading; paragraphs(b)(7) (ii) and (iii) are redesignated as(b)(7) [i) and [ii) respectively.

Section 178.337-11

In response to NTSB recommendationH-90-91 dealing with release of sulfurdioxide from an MC 331 cargo tankduring unloading, RSPA proposedrevision of requirements for remotelycontrolled self-closing stop valves onliquid or vapor discharge lines on newlyconstructed MC 331 cargo tank motorvehicles. Currently found at paragraph(a)(2), this requirement applies only toequipment intended for transportationof a flammable liquid, a flammablecompressed gas, hydrogen chloride(refrigerated liquid) or anhydrousammonia. RSPA proposed to broadenthe requirement to include allcompressed gases. This revision alsowas proposed for MC 338 cargo tanks.

Both the NTSB and the CompressedGas Association (CGA) commented onRSPA's proposal to require remotelycontrolled internal self-closing stopvalves. While supportive of RSPA'sproposal, NTSB stated:

Although the Safety Board is aware thatMC 331 cargo tanks are predominantly usedfor the transportation of flammable andnonflammable compressed gases, thehazardous materials regulations (49 CFRParts 171 through 180) do authorize thesetanks to be used for the transportation ofother classes of hazardous materials such asflammable liquids and poisons. The SafetyBoard believes that remote controls forinternal shut-off valves should be requiredfor any hazardous material that is authorizedto be transported in an MC 331 cargo tank.Further the Safety Board believes that all MC331 and MC 338 cargo tanks currently inhazardous materials service, and not justnewly constructed tanks, should also beequipped with remote controls for theinternal shut-off valves. The Safety Board has-consistently urged the DOT to eliminate"grandfathering" clauses that permithazardous materials to be transportedindefinitely in containers or vehicles that failto meet current minmunum safety standards.The Safety Board believes that RSPA shouldrequire all MC 331 and MC 338 highwaycargo tanks in hazardous materials service tobe equipped with remote controls for internalshut-off valves by a specific date.

On the other hand, the CGA believesthat remotely controlled shut-off valvesshould not be required fornonflammable ladings. CGA stated that

55164 Federal Register / Vol. 59, No. 212 / Thursday November 3, 1994 / Rules and Regulations

"operating experience for thenonflammable compressed gases doesnot warrant the addition of thisrestriction which would add costwithout providing additional safetybenefit."

After consideration of both comments,RSPA has revised the wording in§§ 178.337-11 and 178.338-11 torequire the use of remotely controlledinternal self-closing stop valves on anycargo tank motor vehicle certified afterAugust 31, 1995, that is intended for thetransportation of hazardous materialsother than argon, carbon dioxide,helium, krypton, neon, nitrogen, andxenon. RSPA has excepted theseparticular gases because they pose alesser degree of risk to public health,safety and the environment in the eventof their release during transportation.Many of the nonflammable refrigerantgases presently transported in cargotanks are ozone depleters; some othernonflammable gases are toxic ornoxious. RSPA will address the retrofitof existing cargo tanks with remotelycontrolled internal self-closing stopvalves in a separate rulemaking action.

Section 178.338-9As proposed in the NPRM and

adopted in this final rule, paragraph(c)(2) is amended by removing thedefinition of "same design" and byadding a reference to the definition of"same design" contained in § 178.320.By referencing the definition in§ 178.320, minor design variations areallowed for MC 338 cargo tanks.

Section 178.338-11NTSB and CGA submitted comments

to this section which were similar totheir comments to proposed § 178.33.7-11. As stated in the preamble discussionto § 178.337-11 above, RSPA hasrevised the wording in §§ 178.337-11and 178.338-11 to require the use ofremotely controlled internal self-closingstop valves on any MC 338 cargo tank'motor vehicle certified after August 31,1995, that is intended for thetransportation of hazardous materialsother than argon, carbon dioxide,helium, krypton, neon, nitrogen, andxenon.

Section 178.345-1In paragraph (c), definitions for

"normal operating loading" and"extreme dynamic loading" are added.These terms are used in revised§ 178.345-3 in this final rule.

Paragraph (i)(2) requires that the voidspace within the connecting structure of'a cargo tank motor vehicle composed ofmultiple cargo tanks must be vented tothe atmosphere by a drain of at least 1

inch in diameter. In the NPRM, RSPAproposed to remove the drain hole sizerestriction. RSPA also solicitedinformation on suitable dimensionalcontrols for these drains, how oftenthese areas need to be inspected, theconditions revealed during suchinspections, and the availability ofequipment for inspecting these areas.

Commenters expressed diverse viewson the need to inspect these areas. TheCalifornia Highway Patrol (CHP)strongly supported the need for periodicinspection of the connecting structureson cargo tanks used to transport allhazardous materials. CHP relatedinformation about three separatecatastrophic failures of molten sulfurtrailers that occurred due to fatiguecracking in the void space. All threecargo tank motor vehicles had beeninsulated, thus preventing any externalvisual inspection for shell cracks. CHPbelieves that if an internal visualinspection of the void space had beenperformed, evidence of cracking mayhave been detected prior to thecatastrophic failures. CHP noted thatequipment, such as fiber optics,borescopes and video cameras, isreadily available for inspecting closedareas and is being used for pipeline,aircraft, oil well, and boiler inspections.Also, numerous contractors offeringinspection and non-destructive testingservices are available throughout theU.S.

NTSB also concurred that regular andeffective inspections of void spaces areessential. NTSB, however, expressedconcern that HM-183C did not addressthe configuration of otherappurtenances that could concealcorrosion that might lead to a failure ofthe tank wall. The NTSBrecommendation H-83-30 called forperiodic external visual inspection ofsurfaces obscured by appurtenances,structural members, etc.

Several commenters who opposedinspecting these areas stated.that doublebulkheads and void spaces on MC 306or DOT 406. cargo tanks in non-corrosiveservice do not experience the samedegree of deterioration as MC 312 orDOT 412 cargo tanks in corrosiveservice. They stated that cargo tanks innon-corrosive service should not besubject to the same inspections. Onecommenter submitted to RSPA samplestaken from bulkheads adjacent to voidspaces of two scrapped MC 306 carbonsteel cargo tanks used in gasolineservice for 14 and 15 years. Thecommenter stated that neither tankshowed evidence of corrosion at thislocation; the samples confirm thisstatement.

TTMA stated there is little possibilityof corrosion occurring in the void spaceof any tank, except on carbon steel cargotanks in corrosive service. TTMArecommended that the connectingstructure on self-supporting cargo tanksbe thickness tested every two years forsigns of corrosion. Several othercommenters supported TTMA'scomments. One commenter alsosuggested that the wording be revised toeliminate reference to the inspectionopening but continue to provide for adrain. The commenter stated that theminimum acceptable size of any drainopening should be 0.5 inches diameter,which is large enough to insert aborescope or equivalent device.

RSPA agrees with commenters thatthere has been no evidence of corrosionoccurring in the void space of any tank,except a carbon steel cargo tank incorrosive service. Corrosion mconnecting spaces has serious structuralimplications for self-supporting cargotanks. The failure reported in the NTSBinvestigative report, contamngrecommendation H-83-30, involved acarbon steel MC 312 cargo tank semi-trailer carrying hydrochloric acid; thefailure occurred due to severe corrosionin the tank shell under a circumferentialreinforcing ring. Therefore, paragraph(i)(2) is revised to require that theconnecting structure in a carbon steel,self-supporting multi-tank cargo tankmotor vehicle must have a single drainof at least 1.0 inch diameter, or two ormore drains of at least 0.5 inchesdiameter, 6 inches apart, one of whichis located on the bottom centerline. Inaddition, § 180.407(i) is revised torequire thickness testing of these areasas suggested by TTMA.

RSPA believes that NTSBrecommendation H-83-30, which callsfor periodic external visual inspectionof cargo tank surfaces obscured byappurtenances and structuralattachments, is adequately addressed incurrent § 180.407(d). Paragraph (d)requires that a periodic external visualinspection must be conducted of allmajor appurtenances and structuralattachments on a cargo tank to detectsigns of corrosion or damage.

Section 178.345-3Commenters expressed concern over

the lack of flexibility in calculatingcompressive stresses for non-ASMEDOT 400-series cargo tanks. Theyrecommended that RSPA providealternatives to ASME Code Section VIII,Division 1 UG-23(b) for calculating themaximum allowable compressivebuckling stress in tank walls for lowpressure cargo tanks. The static designand construction of all DOT 400-senes

No. 212 / Thursday November 3, 1994 / Rules and Regulations 55165

cargo tanks must be in accordance withSection VIII of the ASME Code. AnyDOT 400-series cargo tank which isrequired to be certified to the ASMECode also must be designed inaccordance with the Code'srequirements for dynamic loading,including UG-23(b). This applies toDOT 407 cargo tanks with a MAWPgreater than 35 psig and each tankdesigned to be loaded by vacuum, andto DOT 412 cargo tanks having a MAWPgreater than 15 psig.

TTMA stated manufacturers believethe requirements in § 178.345-3(b)should be modified to allow severalmethods of analysis as appropriate forthe cargo tank under consideration.Using the methods outlined in theASME Code produces lower allowablecompressive stress values, resulting insubstantially thicker sheets for the DOT400-senes tanks as compared with theMC 300-senes cargo tanks.

One commenter stated that while theUG-23(b) calculations may beappropriate for DOT 407 cargo tank withMAWP ratings between 25 and 35 psig,this formula will rarely yield reasonableresults for DOT 406 or DOT 412 cargotanks having a:MAWP of 15 psig or less.Commenters recommended twoalternatives to the ASME UG-23[b)design calculations, both of which areformulas from engineering texts. One isfrom the "Alcoa Structural Handbook,"1960, page 156 and Table 23; the otheris from "Formulas for Stress andStrain," Fifth Edition, by Roark andYoung, pages 554 and 555 and Table 35.The "Alcoa Structural Handbook"formula is as follows:

SC =SbA 4 2,J1.5 - Y

where:RjIt is greater than 200E = modulus of elasticity of matenal at

design temperatureR= inside radius of the shell (largest

radius of non-circular cross-section)t.,= minimum thickness of shell less

corrosion allowanceSbA = critical compressive buckling

stress per the Alcoa formulaS = allowable compressive stress due to

static bending loadsThe Roark and Young formula is as

tollows:

Sc = SbY = Ets1.5 (1.5)2(3)y2 [I1- v" V R,

where:Ri/t. is greater than 10SbY = critical compressive buckling

stress per Roark and Youngv = Poisson's ratio

Other symbols are the same as in the-Alcoa formula, above.

Based on the merit of thesecomments, RSPA is revising paragraphb) to allow alternative methods fordetermimng compressive bucklingstress for DOT 400-series cargo tankswhich are not required to be certified inaccordance with the ASME Code. Thisallows manufacturers more freedom i-the design of DOT 400-series cargo tankmotor vehicles, particularly the DOT406 cargo tank.

RSPA solicited information on thestructural integrity of cargo tanks and,in particular, the loading combinationsthat may be encountered duringoperation of cargo tank motor vehiclesas prescribed in paragraph (c).Information was received from severalcommenters which indicated that theloadings from normal operatingconditions are different from loadingsexperienced in extreme dynamic events.The normal operating loadings are morefrequent in occurrence, but much lowerthan the extreme dynamic loadings.

The requirement contained in currentparagraph (c) only specifies extremedynamic loadings. A cargo tank designermust determine which loadings, if any,should be considered as actingsimultaneously. TTMA stated it isunlikely that extreme dynamic loadingswill occur and lghly unlikely that suchloadings will occur at the same time.TTMA reported that if the extremedynamic loadings are considered by thecargo tank designer as actingsimultaneously, the resulting weight ofa DOT 406 cargo tank would increasesignificantly. TTMA went on to statethat such an increase in tank weightwould have an adverse effect on publicsafety because it would cause a decreasein the number of gallons delivered eachtrip, increasing the number of trips andmiles driven, thus increasing theprobability of more accidents, personalinuries and fatalities.

During discussions on structuralintegrity issues at the February 1994public meeting, the potential forchanges in loading due to liquidmovement was addressed. Commentersgenerally agreed that while significantlading movement can occur duringpartially loaded conditions and thatsuch movement cannot be disregardedby cargo tank designers and vehicle

operators, the variables involved aremore than can be comprehensively dealtwith at tins time. The general agreementwas that the highest stress conditions onmost cargo tank configurations occurwhen the cargo tanks are full.Discussions on how to combine theloadings in calculating the structuralintegrity requirements have been goingon for a number of years. RSPA agreeswith commenters that the loadingscurrently in the HMR are based onextreme conditions that would berealized only on a rare occasion, if ever.Thus, based on recent informationpresented at the public meetings andwritten comments received in responseto the NPRM, RSPA concludes that, forthe design and construction of cargotanks, it is best to consider separatelythe effects of normal operating loadings,which are known to act in combination,and the effects of extreme dynamicloadings, which are not expected to actin combination with each other.Therefore, in this final rule, RSPA isrevising paragraph (c) to providestructural design requirements that willbe more reflective of conditionsencountered by cargo tank motorvehicles. These revisions will requirecargo tank designers to consider normaloperating loadings to be actingsimultaneously except that longitudinalacceleration and deceleration cannotoccur at the same time. Also, extremedynamic loadings must be considered inseparate calculations; these loadingsmay be considered to be actingindependently.

Paragraph (d) prescribes designcalculations that should be consideredto account for stresses due to impact inan accident. For consistency, theaccident damage requirementscontained in current paragraph (d) aremoved to §178.345-8(e) where otheraccident damage protectionrequirements appear. Also, consistentwith other changes made to this section,paragraphs (a) (1) and (3) are amendedby removing the reference to paragraph(d) of this section.

Paragraph (e) is editorially revised, forclarity and consistency, by changing theword "wall" to read "shell and heads"and paragraphs (e) through (g) areredesignated as paragraphs (d) through(f).Section 178.345-5

Commenters supported the proposedchange in paragraph (b) that all fittingsand devices mounted on a manholecover must withstand the same staticinternal fluid pressure as that requiredfor the manhole. However, commentersrequested a revision to clarify thatfitting and device manufacturers are

Federal Register / Vol. 59,

55166 Federal, Register / Vol. 59, No. 212 / Thursday November 3, 1994 / Rules and Regulations

responsible for testing and certifying thestructural integrity of their products.

-RSPA agrees with the commenters thatthe fitting and device manufacturersshould be responsible for ensuring theintegrity of their components. Therefore,the proposed provision is revised forclarity and added as new paragraph (f).

Another commenter suggested thatparagraph (e) be revised to require thateach manhole cover must be markedwith the date of certification. RSPA willconsider this comment in a futurerulemaking action.

Section 178.345-6

A minor editorial change is adoptedas proposed in the NPRM.

Section 178.345-8

Commenters recommended severalchanges to the accident damageprotection requirements. They requestedthat all accident damage protectiondevices be designed so that calculatedstress under the conditions prescribednot exceed the ultimate strength of thematerial of construction. They pointedout certain inconsistencies in the designcriteria specified in this section. Forexample, in paragraph (d), the designstress for accidents involvinglongitudinal deceleration is based on"the lesser of the yield strength or 75percent of the ultimate strength"- thegeneral requirement for accidentdamage protection in paragraph (a)(3), isbased on "75 percent of the ultimatestrength"- while bottom damage androllover damage protection, inparagraphs (b) and (c), both are based onthe "ultimate strength. RSPA agreesthere is merit in using the same criteriawhenever possible. Therefore, in thisfinal rule, the design of all accidentdamage protection devices is based onthe ultimate strength of the material ofconstruction.

The primary purpose of accidentdamage protection is to prevent therelease of hazardous lading from a cargotank m the event of an accident. Forexample, during an accident involvingthe maximum level of longitudinaldeceleration expected, if the front headof a cargo tank experiences stress levelsabove the yield point of the material ofconstruction, the head will bulge ordistort. However, if that deformed headcontinues to contain the lading, theintent of this requirement has' been met.In a practical sense, good engineeringpractice provides for factors of safetywhen analytical methods are not wellestablished and when safetyconsiderations call for reducing theprobability of failures.

When an accident imposes loads onthe cargo tank wall, the material of the

wall, however, must be stronger thanthe accident damage protection device.For example, in a rollover accident,-theportion of the cargo tank wall to whicha rollover protection device is attachedshould not fail before the rolloverprotection device fails. The designstresses in the protection device itselfcan be based on the ultimate strength ofthe material, but the loads transmittedto the cargo tank wall must be based ona more conservative value. This can beachieved by use of factors of safety.

Accordingly paragraph (a)(3) isrevised to base design stresses on theultimate strength of the material with a1.3 safety factor (i.e., the reciprocal of0.75 times ultimate, rounded).

Commenters have stated that mostimpacts on bottom damage protectiondevices in accidents occur directly fromthe side of the vehicle. TTMA has statedthat any piping at the bottom of a tankis protected fore and aft by the runninggear of the cargo tank motor vehicle orits towing vehicle. Contending thatreduced forces of impact can beexpected from front and rear, TTMApetitioned for a reduction from 155,000pounds to 27,000 pounds fore and aftalong the longitudinal axis of thevehicle. RSPA believes, however, thatthe possibility of impacts from the frontis very real for trailers; for example,during turning maneuvers, or in theevent that the towing vehicle rides overan obstacle such as a guard rail. On theother hand, impacts from the rear areless likely on trailers because of the rearsuspension. Therefore, RSPA hasrevised paragraph (b)(1) to recognizethat suspension components andstructural mounting members canprovide all, or part, of bottom damageprotection. Additionally, in paragraph(b) introductory text, a second sentenceis added to clarify that a singleprotection device may be used to protectoutlets, projections and piping groupedor clustered together.

Commenters stated that in the generalrollover damage protectionrequirements, in paragraph (c), thewording "enclosed inside" could bemisunderstood to require that closuresand fittings must be protected from-rollover damage on all sides-front,sides, rear and top. They also suggestedthat the protection devices be located nomore than 48 inches from the closure orfitting. RSPA never intended to require.that the component being protected befully enclosed by the protective device.Also, RSPA does not agree with addinga dimensional location requirement.Rather than dimensional controls, oneof RSPA's overall objectives is toprovide performance requirementswhen appropriate. Therefore, paragraph

(c) is revised to clarify the ambiguouswording.

Commenters requested that inparagraph (c)(1), the tangential designload for rollover protection be reducedfrom 2 "g" to 0.5 "g" or I "g." Acommenter stated that "neither industrynor government have any data tosupport what this rollover protectiondevice strength should be" contendingthat MC 306 accident damage protectionhas performed well, even consideringfindings of the NTSB study of overturnaccidents. A commenter providedanalytical data that indicated theinternal bulkheads would beoverstressed under 2 "g" tangentialloads using the current MC 306 design.

A February 4, 1992 NTSBinvestigation report on rolloveraccidents involving MC 306 and MC 312cargo tanks recommended severalactions by both RSPA and the FederalHighway Administration (FHWA). TheNTSB report supported the earlier RSPAdecision to increase the rollover designload in the horizontal plane from one-half the weight of the loaded cargo tankmotor vehicle prescribed in the MC 306,MC 307 and MC 312 specifications, totwice the weight of the loaded cargotank motor vehicle prescribed in theDOT 406, DOT 407 and DOT 412specifications. NTSB also noted that atthis time, test results are not" availableto support this four-fold increase, butlimited testing performed under RSPAand FHWA sponsorship for studies ofrelease from dome covers indicate forcescan easily exceed 2 "g" AdditionallyNTSB questioned whether the loadspecified for the DOT 406, DOT 407 andDOT 412 specifications are adequate ina typical rollover accident.

RSPA agrees with comments that insome rollover accidents, cargo tankrotation is limited to 120 degrees or less,so that these horizontal forces do notcome into play unless a roadsideobstacle is struck. In such incidents, theside of the cargo tank absorbs most ofthe energy of the rollover. However, inother rollover incidents, cargo tankmotor vehicles have rotated 180 degreesor more and rollover protection deviceshave failed.

RSPA performed simple calculationsto estimate the forces that would beexpected to bring a sliding overturnedcargo tank motor vehicle to a halt, at avariety of speeds and stoppingdistances. From the calculationsperformed regarding stopping distances,RSPA concludes that the design loadsshould not be decreased. FHWA willinitiate a study aimed at developing amore refined understanding of theforces involved in cargo tank rolloveraccidents.

Federal Register / Vol. 59, No. 212 / Thursday November 3, 1994 / Rules and Regulations 55167

For these reasons, RSPA rejectsrequests to lower the tangential designload. In many cases, manufacturers willfind it necessary to develop new designsfor overturn protection devices, perhapswith associated short-term increasedcost, but with enhanced safety benefits.Several manufacturers already havedeveloped satisfactory protectiondevices which meet these designcriteria. In addition, RSPA has madeseveral minor editorial revisions inparagraph (c)(1) to improve clarity.

Paragraph (d)(3) prescribes that eachcargo tank rear-end protection deviceand its attachment to the vehicle mustbe designed to satisfy ihe conditionsspecified in paragraph (d)(1) whensubject to an impact of the cargo tank atrated payload, at a deceleration of 2 "g"Such an impact must be considered asbeing uniformly applied in a horizontalplane at an angle of 30 degrees or lessto the longitudinal axis of the vehicle.Commenters requested elimination ofthe 30 degree angle for this impact load.They stated that most rear-endcollisions of trucks and trailers involveother vehicles and are "in line" i.e., thelongitudinal centerlines of the twovehicles are parallel at impact. TTMApointed out that the National HighwayTraffic Safety Administration (NHTSA)published a notice of proposedrulemaking (Docket No. 1-11, Notice 9;January 3, 1992], containing a proposalfor rear impact guards and protection.The NHTSA proposal specified animpact only in the direction of thelongitudinal centerline of the struckvehicle; it did not address angularimpact. NHTSA's rear impactrequirements are intended for the designof undernde guards that will minimizeimpacts in occurrences whereautomobiles underride (i.e., slide under)the rear-end of large trucks and trailers.These requirements are intended toprotect passenger occupants whileRSPA's requirement for cargo tank rear-end protection is intended to preventimpacts to lading retention componentsthat could result in the loss ofhazardous material lading. Upon furtherreview, RSPA agrees that requiring rear-end protection devices to withstandimpacts at an angle of 30 degrees to thelongitudinal axis of the vehicle isexcessive. Therefore, paragraph (d)(3) isrevised to reduce the angle of impact to10 degrees.

A requirement contained in currentparagraph (d) of § 178.345-3 specifyingdesign stress for accidents involvinglongitudinal deceleration is revised andmoved to new paragraph 178.345-8(e)in this final rule. The specified designstress is based on the ultimate strengthof the material with a factor of safety of

1.3 (i.e., the reciprocal of 0.75 timesultimate, rounded). The use of 2 "g" asa reasonable maximum level forlongitudinal deceleration in accidentsituations generally has been acceptedby industry but commenters have statedthat the reliability of strain gauge testingand finite element analysis isquestionable when structures are loadedabove the yield point. For this reason,cargo tank manufacturers who choose todesign at this level may useperformance testing to prove that tankheads and shell can withstand this 2 "g"loading condition. Alternate analyticalmethods or combinations of test andanalysis may be used if they areaccurate and verifiable.

Section 178.345-10This section specifies requirements

for the pressure relief and vacuumsystems on DOT 400-series cargo tankmotor vehicles. It also specifies ladingretention requirements for the pressurerelief system in the event of an overturn.Numerous commenters suggestedalternative provisions for pressure reliefsystems on DOT 400-series cargo tanks.Pressure relief valve manufacturersstated that they have found it verydifficult to attain "no loss of lading"with valve designs capable ofwithstanding the characteristic dynamicpressure surge required by theregulation, especially at low designpressures.

'For these reasons, commentersrequested that RSPA allow the loss ofone liter of lading. If adopted, a properlyfunctioning pressure relief valve couldbe expected to release no more than oneliter of hazardous material in anoverturn accident. This amount ofliquid would be so widely dispersed bythe motion of the vehicle as to causemimmal danger of fire or environmentaldamage.

Cargo tank shipments of poisonous-by-inhalation .(PIH) materials in HazardZones A and B are subject to specialprovisions which result in high workingpressures, thicker tank walls andthermal insulation. Insulationmoderates thermal-gain, thus increasingthe pressure differential between valvepressure settings and dynamic pressure;also, it cushions the impact of accidents.The net effect of these features makes itunlikely that even small releases of PIHlading will occur.

RSPA believes allowing a minuterelease of other types of ladings inoverturn accidents has greater safetybenefits when compared with possibleloss of an entire cargo tank load.Therefore, paragraph (b)(3)(ii) is revisedto specify that after August 31, 1995,DOT 400-series cargo tanks must be

equipped with a pressure relief valvethat will release no more than one literof lading in an emergency situationbefore reclosing to a leak-tight position.In addition, editorial changes are madein paragraph (b)(3)(i) for clarity.

Section 178.345-13A paragraph heading, "Leakage test.

is added to paragraph (c) as proposed inthe NPRM.

Section 178.345-14

This section specifies cargo tankmarking requirements. The CaliforniaHighway Patrol recommended severalsubstantial changes throughout thissection that were not proposed in theNPRM. While RSPA believes some ofthese changes may have merit, they willhave to be considered in a futurerulemaking.

Proposed paragraph (d) is revised toclarify that each cargo tank on a multi-tank cargo tank motor vehicle must havea separate nameplate, unless each cargotank is made by the same manufacturerwith the same materials, manufacturedthickness, and mimmum thickness.

Section 178.345-15RSPA proposed to add a new

paragraph (e) to allow affixing a metalcertification plate to cargo tanks whichdo not meet all of the applicablespecification requirements. This wouldbe indicated by not stamping acompliance date on the plate. Acommenter pointed out that theproposed wording does not specificallyrequire the Registered Inspector tostamp the date of compliance on thespecification plate when the cargo tankis brought into full conformance withthe specification. RSPA agrees with thecommenter and has clarified therequirement.

Another commenter requested arevision to clarify that, for ASME tanks,the cargo tank motor vehiclemanufacturer must furnish amanufacturer's data report to the cargotank owner as required by the ASMECode, in addition to other requireddocuments. The ASME Code requires acargo tank manufacturer to prepare amanufacturer's data report for each tank.RSPA agrees with the commenter andhas added a provision in paragraph(b)(2) specifying that the manufacturer,must supply the cargo tank owner witha copy of the manufacturer's data report,at the time of delivery.

Section 178.346-1RSPA proposed to add a new

paragraph (d)(9) specifying provisionsfor the use of a single full fillet lap weld.joint without plug welds for

55168 "Federal. Register / Vol. 59, No. 212 / Thursday,. November 3, 1994 / Rules and Regulations

longitudinal seams on the top 25.percent of the cargo tank. For the mostpart, commenters agreed in principalwith the proposal; however, theyrecommended that the use of singlefillet weld lap joint not be limited to thetop one-fourth of the cargo tank.

Several manufacturers stated that theyhave used single full fillet lap weldedjoints for longitudinal seams on both thetop and bottom areas of thousands oflow-pressure cargo tank motor vehicles.They stated their service experiencewith these joints over many years ofoperations has been very good.

Advantages cited by themanufacturers for using this type ofweld include the ability to achieveexcellent fit between the shell and headflanges, and reduction in the amount oftime personnel must work in confinedspaces. However, because the ASMECode does not recognize this jointconfiguration, it may not be used onASME certified vessels.

Industry submitted reports of tensiletests of the typically used single fullfillet lap joints to RSPA. Test resultsindicate that failure occurs at stresslevels of about 70 to 75 percent of.theultimate strength of adjacent material.One commenter opposed the use of suchjoints but provided no supporting testdata.

RSPA believes the satisfactoryperformance of these joints over theyears serves as a persuasive argumentfor their continued use on DOT 406cargo tank motor vehicles. However,because a major reason for establishingthe DOT 400-series specifications isenhanced quality assurance, the jointsmay be used only when subject tocertain conditions. Therefore, newparagraph (d)(9) specifies the conditionsfor use of these joints in longitudinalseams, requirements for periodiccompliance testing, and designrequirements for determimng weld jointefficiency. In addition, a new paragraph(d)(10) is added to clarify thatrequirements of paragraph UW-9(d), ofSection VIII, Division 1, ASME Code donot apply.

Section 178.346-2

Minor editorial changes are made toparagraph (a).

Section 178.346-10Valve manufacturers stated-that,

during prototype testing, they haveencountered substantial problems inobtaining adequate flow underemergency conditions with pressurerelief valves designed for thecomparatively low MAWP levels typicalof DOT 406 cargo tank motor ,iehicles.These problems have been resolved for

current valves; however, the valvemanufacturers continue to believe theemergency flow capacities, winch arepermitted to release up.to one gallon oflading under the dynamic pressuresurges characteristic of rolloveraccidents,.are still marginal in somecases. Because of the problemsencountered by valve manufacturersRSPA will allow an additional year forproduct development andmanufacturing start-up. This extensionis added in a new paragraph (b)(3).

RSPA proposed to revise paragraph(c)(1) to permit DOT 406 cargo tanks tohave the same set pressure and testpressure as allowed in § 178.345-1o(d)(1), and as prescribed for DOT 407and 412 cargo tanks except that thereclosing pressure would remain at noless than MAWP Commenters statedthat while the proposed language wouldbe helpful in increasing the ventingcapacity to a limited extent andproviding a similar difference betweenopening and closing pressures over arange of MAWP values, it would noteliminate the need for supplementaryventing capacity. Commenters requestedthat the flow rate be determined at ahigher pressure, specifically at 125percent of the tank test pressure. Tinswould provide more pressuredifferential across the valve seat andprovide higher venting capacities. Asdiscussed in the preamble for 178.346-10(b) above, pressure relief valvemanufacturers reported that they havefound it difficult to obtain adequateemergency flow capacities in valvesdesigned for DOT 406 cargo tank motorvehicles.

Based on comments received, RSPAbelieves the problem can be relieved byimplementing two measures. The firstmeasure is to increase the tolerance onthe valve set pressure to allow the valveto begin opening at a lower set pressureand to be fully open at a higherpressure. The second measure is toincrease the venting capacity ratingpressure to 125 percent of the tank testpressure, and not greater than 3 psiabove the tank's MAWP Because thepressure relief valves are required to beremoved from the cargo tank duringperiodic pressure testing, the tank itselfwill not be exposed to pressures aboveits normal test pressure [see§ 180.407(g)(1)(i)]. Tins increase in theventing capacity rating pressure willstill provide a satisfactory margin ofsafety with respect to tank burstingpressure, even in the event of exposureto fire. The combined effect of thesechanges can be expected to significantlyraise the pressure differential across thevalve seat, thus increasing flow.Accordingly, both paragraphs (c)(1) and

paragraph (d)(1) have-beenrevised toinclude these two measures.

Section 178.346-13

In the NPRM, RSPA proposed toincrease the emergency flow capacity ofDOT 406 pressure relief valves byraising the test pressure of the cargotank. This was intended to alleviateproblems reported by valvemanufacturers by increasing thedifferential pressure across the valveseat, thus increasing flow. However,commenters requested that RSPA notmake this change because of theincreased danger of deformation ofheads at pressure levels above 5.0 psig,especially for internal heads in whichthe pressure is applied to the convexside. One commenter stated thatpressures above 5.0 psig would requireincreased head thickness or bracing;thus increasing the weight of the tankresulting in lower payload and highermanufacturing cost.

As an alternative means of increasinemergency flow, commenters suggestedthat the set pressure and the flow ratingpressure of the pressure relief valveitself be changed while retaining theexisting tank test pressure..RSPA agreeswith this alternative. Therefore, RSPAhas revised paragraphs 178.346-10(c)(1)and (d)(1) instead of revising the tanktest pressure requirements.

Shortly before publication of theNPRM, TTMA petitioned RSPA to usethe Environmental Protection Agency(EPA) test for vapor-tightness for allDOT 406 cargo tanks. TTMA requestedthat Method 27 be authorized for allDOT '406 cargo tanks, regardless ofwhether they are: (a) used in gasolinedelivery, (b) fitted with vapor collectionequipment, or (c) subject to this testunder EPA rules. Method 27 is foundin appendix A. to 40 CFR Part 60.Section 1.1 of Method 27.is applicablefor the determination of vapor tightnessof a gasoline delivery tank which isequipped with vapor collectionequipment. Requirements for applyingthe initial pressure-vacuum and testcriteria are contained in 40 CFR Part 60,Subpart XX-Standards of Performancefor Bulk Gasoline Terminals. In§ 60.501, the definition of vapor tightgasoline tank truck reads:

Vapor-tight gasoline tank truck means agasoline tank truck which has demonstratedwithin the 12 preceding months that itsproduct delivery tank will sustain a pressurechange of not more than 750 pascals (75 mmof water) within 5 minutes after it ispressurized to 4,500 pascals (450 mm ofwater). This capability is to be demonstratedusing the pressure test procedure specified inReference Method 27

No. 212 / Thursday, November 3, 1994 / Rules and Regulations 55169

It should be noted that 750 pascals =0.109 psi = 3.0 inches of water and4,500 pascals = 0.653 psi = 18.1 inchesof water. Similar provisions for benzeneare prescribed in 40 CFR Part 60,Subpart BB-National EmissionStandard for Benzene Emissions fromBenzene Transfer Operations, at§60.601.

RSPA authorized this alternativeleakage test in the June 12, 1989 finalrule published under HM-183 to relieveburdens of duplicate test requirementsfor cargo tanks intended for use inlocations where, based on establishedstandards of air quality, EPA hasdecided that release of gasoline vaporsconstitutes a hazard to the environment.TMA stated that a cargo tank motorvehicle manufacturer may not know thelocal air pollution requirements towhich the motor vehicle may be subject.RSPA recognizes TTMA's concerns andis permitting this alternative test whena cargo tank is equipped with vaporrecovery equipment withoutqualification regarding the materialstransported. RSPA also has revisedparagraph (c) and § 180.407(h)(2)toreference appropriate acceptancecriteria in EPA's regulation contained in40 CFR 60.

Section 180.403

Commenters supported the proposalto add a definition for the term"replacement of a barrel." TT'MArecommended that, in the definition of"replacement of a barrel" the wordingAunused tank" should be clarified tomean a "new tank." RSPA agrees andthe word "new" is addedparenthetically after the word"unused."

Commenters also supported theproposal to revise the definition ofrebarrelling. However, for the reasonscontained in the preamble discussionfor § 180.413 the proposed revision isnot being adopted in this final rule. Aconunenter recommended that thedefinition of "repair" be modified toinclude the replacement of componentssuch as valves, vents and fittings. RSPAbelieves this suggested change would beconfusing because a "repair" isspecifically defined to mean "anywelding done to the cargo tank wall toreturn it to the original specification ora later equivalent specification."Replacement of valves, vents andfittings is considered maintenance.Therefore, the current definition isretained.

Section 180.405

Minor editorial changes are made insubparagraphs (f{)(1}iii) and (f)(4) asproposed in the NPRM.

In paragraph (g)(2), RSPA proposed toclarify that fittings and devices mountedon a manhole cover are part of themanhole assembly and must meet allperformance standards required for themanhole cover. A commenter stated thatthe current requirement is adequate andrecommended that RSPA not adopt theproposed change. The commenter statedthat any concern or problem is due toa lack in verifying the continued propersecurement of these fittings and devicesto the manhole cover. The commentersaid that the annual leakage test andinspection requirements in § 180.407should be sufficient to assure that thesein-service fittings and devices remainsecurely mounted and properly sealedon in-service manholes. RSPA agreeswith the commenter and the proposedchanges are not adopted in this finalrule.

Another commenter recommendedthat paragraph (g)(2)(i) be revised to add"month and year" to the certificationmarking on manhole assemblies.Although RSPA believes that such arequirement may have merit, anopportunity should be provided forpublic comment; therefore, it will beconsidered in a future rulemakingaction.

Paragraph (h) specifies thatreplacement for any reclosing pressurerelief valve must be capable of re-seatingto a leak-tight condition after a pressuresurge. Section 180.405(c) authorizesmodifying the reclosing pressure reliefvalves of an MC 306 cargo tank byinstalling the dual function pressurerelief valves which are required for DOT406 cargo tank motor vehicles.Commenters pointed out that thisreplacement could result in an MC 306cargo tank having lower emergencyventing capacity than its specificationrequires; because it is difficult toproduce a valve that achieves thecomparatively high flow rates of the MC306 units, withstands the pressuresurges specified in the DOT 406specification, and recloses with minimalloss of lading. A reduced flow capacityis less likely to be encountered in fittingan MC 307 with a DOT 407 valvereplacement, and in fitting an MC 312with a DOT 412 valve replacement,because of the larger pressuredifferentials which are-commonly usedin these cargo tanks. Regardless of theequipment installed, the ventingrequirements specified in the particularcargo tank specification must be metwhenever a pressure relief valve isreplaced. For this reason, in this finalrule, RSPA is authorizing replacementof defective MC 306 pressure reliefvalves with new or refurbished MC 306pressure relief valves until August 31,

1998. After this date, any valvereplacements must be the surge resistantpressure relief valves required for DOT400-series cargo tanks. This allows threeyears for implementation of this safetyapprovement.

Section 180.407In the table in paragraph (c), chlorine

cargo tanks must be leakage testedannually These cargo tanks are alsorequired to be pressure tested every twoyears. Based on a comment, RSPA hasextended the frequency for conductingthe leakage test to two years to coincidewith the pressure test. Certain minoreditorial changes are made in paragraph(d}(1)(i) for clarity. Paragraph (e)(1) isrevised to clarify that when a particulartank design such as a cargo tank with alining, coating or internal baffles,precludes an internal visual inspection,the tank must be hydrostatically orpneumatically tested. Paragraph (e)(4),which is duplicative with therequirements in paragraph (f)(3), isremoved as proposed in the NPRM.

RSPA proposed to revise paragraph(g)(1)(iv), covering the pressure test ofspecification cargo tanks for consistencywith theproposed changes to § 178.346-10; however, commenters who initiallysought this.change recommended thatthe proposal be withdrawn and thecurrent provisions retained. Therefore,no change is made in this final rule.

Paragraph (h)(2) is revised to permitthe use of the EPA Method 27 vaportightness test on any cargo tank fittedwith a vapor recovery system and usedin gasoline or benzene service, asdiscussed earlier under the preamblediscussion to § 178.346-13(c)(2). Acommenter suggested that paragraph(h)(2) require the use of oil or soap todetect leaks in cargo tank seams, piping,valves and accessones when performingthe Method 27 test. RSPA believes thatoil or soap can be very useful in locatingleaks, but that it would be anunnecessary burden if required for allMethod 27 tests. Accordingly RSPA hasnot adopted the suggested change.

Paragraph (i) prescribes that the headsand shell of all unlined cargo tanks usedfor the transportation of materialscorrosive to the tank must be thicknesstested. Consistent with changes made to§ 178.345-1(1)(2) in this final rule, anew paragraph (i)(4)(x) is added tospecify that thickness testing must beperformed on connecting structures of acarbon steel, self-supporting multi-tankcargo tank motor vehicle.

Requirements for continuingqualification and maintenance of cargotank motor vehicles include periodicmeasurement of the thickness of headsand shells. This has focused attention

Federal Register / Vol. 59,

55170 Federal Register / Vol. 59, No. 212. / Thursday November 3, 1994 / Rules and Regulations

on interpretation of specificationrequirements for mimmum thickness,especially of specification MC 306, MC307 MC 312 cargo tanks and theirpredecessors.

In the specifications for MC 306, MC307 and MC 312 cargo tanks constructedof steel, minimum thicknessrequirements for heads and shells wereexpressed in terms of U. S. StandardGauges for sheet material or, for someMC 312 units where plate material wasspecified, in terms of fractions of aninch. These data were found at Table Iand Table II in specifications for each ofthe respective types. Although notexplicitly stated in the regulatory text,the tabulated values were the minimumnominal sheet and plate sizes permittedfor these cargo tanks. For aluminum,values in Table I and Table II were theminimum nominal thickness expressedin decimals. The tolerances on millthickness and the minimum thicknessafter forming were not covered.Although major steel purchase ordersand steel mill production controls forsheet stock and thin plate are based onspecific thicknesses and tolerancesrather than on standard gauges,manufacturing tolerances have beenestablished by the American Society forTesting and Materials (ASTM) forstandard gauges and plate. For example,ASTM A480/A480M provides generalspecifications for stainless steels andheat-resisting steel plate, sheet andstrip; Tables A1.2 and A1.17 in thisspecification are of special interest tomanufacturers of DOT specificationcargo tanks. For MC 307 and MC 312cargo tanks which were required to bedesigned and constructed m accordancewith the ASME Code, minimum millundertolerances are set forth in SectionVIII, Division 1 at UG-16(c). The ASMEvalues are more restrictive than those ofASTM A480/A480M.

In January 1'991, the National TankTruck Carriers, Inc. (N'ITC) published arevision to their "Cargo TankMaintenance Manual" wich included atable of minimum thicknesses for U.S.steel gauges ranging from 3 through 30.The accompanying narrative stated thatthe basic information was "provided byDOT A table, contained in§ 173.24(c)(2) of the 1990 edition of theHMR was cited for gauges 12 through 30with extrapolation being used tocomplete the other gauges. The valuespresented in that table were intendedfor relatively severe cold-workingoperations such as those experienced informing the top and bottom chimes ofsteel drums, not for cargo tankconstruction. However, since adopting49 CFR 180 Subpart E-Qualificationand Maintenance of Cargo Tanks, the

values published in the NTTC manualhave been used for thickness testing asrequired by § 180.407(i). In the NPRM,RSPA proposed to add a new paragraph(i)(5) containing a minimum thicknesstable for steel and aluminum for thesizes of sheet and plate which have beenauthorized for MC 300, MC 301, MC302, MC 303, MC 304, MC 305, MC 306,MC 307 MC 310, MC 311, and MC 312heads and shells. The way in whichminimum thickness has been set forthover the years has varied. For example,steel thicknesses generally have beenexpressed in terms of U.S. StandardGauge (USSG), but, in the case of theMC 303 specification, both USSG valuesand-decimal values were used.Thickness values for aluminum moreoften have been expressed in decimals.However, in the case of the MC 302specification, both USSG values anddecimal values were tabulated; and inthe case of the MC 304 specification, thevalues for aluminum were required tobe calculated by multiplying theUSSGvalues listed for mild steel by a factorof 1.44.

TTMA suggested several changes tothe table for clarity. TTMA alsorecommended that the table be dividedinto two separate tables: one for steeland one for aluminum. RSPA agreeswith TTMA's recommendation.Therefore, in this final rule, currentparagraphs (i)(5) through (1)(7) areredesignated as paragraphs (i)(6)through (i)(8), and a new paragraph(i)(5) containing two mimmumthickness tables has been added. Thetables include all thicknesses found inthe eleven specifications cited above,plus USSG number 7 which has beenused by a number of manufacturers. Forsteel, nominal thicknesses range fromUSSG number 19 to 3/8" plate; foraluminum, nominal thicknesses rangefrom 0.078" to 0.540"

Section 180.413RSPA proposed to revise

requirements on the repair,modification, stretching or rebarrellingof cargo tanks. A commenter requesteda revision to the record requirementscontained in proposed paragraph (b) torequire that the National Board "R-1"report be completed for all repairs onASME Code stamped cargo tanks. Thecommenter stated that completing thedocument will ensure that the repairand method of repair conforms to theNational Board Inspection Code and isapproved by an AuthonzedInspector.RSPA believes this revision isunnecessary because § 180.413 requiresthat any repair or modificationinvolving welding on the tank headmust be certified by a Registered

Inspector, and that any repair ormodification to an ASME Code "U"stamped cargo tank must be inaccordance with the National BoardInspection Code. The National Boardrequires the use of the "R-1" forms forrepairs and modifications. Therefore,this commenter's recommendation isnot adopted in this final rule.

RSPA proposed to require that anyrepair, modification, stretching orrebarrelling of an ASME Code-stampedcargo tank must be performed by a-repair facility holding a National Board"R" stamp. The National Board allowsa facility other than a National Board"R" stamp holder to make repairs andmodifications to ASME Code cargotanks when authorized within agovernmental jurisdiction. Jurisdictionalauthorization is only recognized withinstate boundanes where the repairfacility is located. Therefore, becausemost cargo tank motor vehicles areoperated in interstate commerce, RSPAhas adopted the proposal requiringrepairs on DOT specification cargo tankscertified to the ASME Code to beperformed only by a facility holding avalid "R" stamp.

Based on a letter from TTMA statingthat the regulations provide nodistinction between a "100 percentrebarrel" and the manufacture of a newcargo tank, RSPA proposed to clarify therebarrelling requirements and todifferentiate between "rebarrelling acargo tank" and ."manufactunng a cargotank" It was never RSPA's intent toimply that a repair facility holding onlya National Board "R" stamp would beallowed to manufacture a new cargotank or to perform a "100 percentrebarrel" of a cargo tank. Such work canbe performed only by a manufacturerwho is registered with DOT and holdsan ASME "U" stamp. RSPA proposedadding a provision disallowing a repairfacility from replacing an entire cargotank by performing a "100 percentrebarrel.

However, based on commentsreceived in the proposed clarification,the reference to a "100 percentrebarrelled cargo tank" has also causedconfusion. Therefore, the proposedchange is not adopted in this final rule,but RSPA will seek to clarify thisprovision in a future rulemaking.

CGA urged RSPA to add a newparagraph (e)(3)(v) specifying thatmodificatiQns of MC 338 cargo tanksmust conform to the specification ineffect at the time of manufacture or atthe time of modification. CGA pointedout that many cryogenic cargo tankswere operating under DOT exemptionprior to adoption of the MC 338 cargotank specification. Some of these units

Federal Register / Vol. 59, No. 212 / Thursday, November 3, 1994 / Rules and Regulations 55171

do not conform to the design criteria in§§ 178.338-3 and 178.338-10. CGAstated that engineering andmanufacturing costs to upgrade thesecargo tanks to this new design criteriawould be too restrictive. Yet, CGA alsostated that "to encourage continuousmodification and improvement,modifications to MC 338 cargo tanksmust be performed in accordance withthe specifications in effect at the time ofmanufacture or at the time ofmodification."

Proposed § 180.413 provides for acargo tank to be modified in accordancewith a current specification in effect atthe time the work is done. For example,a feature on an MC 305 cargo tank maybe modified in accordance with the MC306 specification until August 31, 1995,and after that date in accordance withthe DOT 406 specification; an MC 330cargo tank may be modified inaccordance with the MC 331specification. Similarly a cargo tankauthorized under an exemption issuedbefore October 1, 1984 for transportationof a cryogenic liquid must be marked asa "DOT MC 338" cargo tank inaccordance with § 180.405(d). The onlycryogenic cargo tank specification is theMC 338. Thus, no feature of an MC 338cryogenic cargo tank can be modified inaccordance with any other specification.However, an MC 338 cryogenic cargotank may be repaired in accordancewith either its original design specifiedin the exemption under which it wasmanufactured or the MC 338specification requirements in effect atthe time of the repair. Therefore, CGA'ssuggested change is not adopted in this-final rule.

CGA recommended a revision toparagraph (e)(6) to clarify that a cargotank manufacturer who weldsattachments and appurtenances whichhave no affect on the structural integrityor lading retention capability of a tankis not required to have a National Board"R" or ASME "U" stamp. CGA alsosuggested a revision to paragraph (e)(7)to clarify that mounting specificationsshould be governed by welding to thecargo tank "shell and head" rather thanthe cargo tank "wall" RSPA agrees andparagraphs (e)(6) and (e)(7) are revisedfor clarity.

IV Docket HM-183DOn September 3, 1993, RSPA

published an interim final rule thatamended requirements concerning theregistration of Registered Inspectors andDesign Certifying Engineers forcertification of cargo tank motorvehicles. RSPA extended the closing ofthe registration period from December31, 1991 to December 31, 1995. This

action was in response to a petition forrulemaking, P-1167 filed by NTTC.RSPA stated in the rule that although anopportunity for public comment had notbeen provided, RSPA was seekingpublic comment to the action. RSPAfurther stated that any commentsreceived would be addressed along withcomments received to the NPRM underDocket HM-183C. The effective date ofthis rule was September 3, 1993. Thecomment period closed on October 13,1993; RSPA received no comments inregard to this action. Therefore, thatextension remains in effect.

V Rulemaking Analyses and Notices

1. Executive Order 12866 and DOTRegulatory Policies and Procedures

This final rule is not considered asignificant regulatory action undersection 3(f) of Executive Order 12866and was not reviewed by the Office ofManagement and Budget. The rule is notconsidered significant under theRegulatory policies and Procedures ofthe Department of Transportation (44 FR11034). A regulatory evaluation isavailable for review in the docket.

2. Executive Order 12612This final rule has been analyzed in

accordance with the principles andcriteria contained in Executive Order12612 ("Federalism"). Federal lawexpressly preempts State, local, andIndian tribe requirements applicable tothe transportation of hazardous materialthat cover certain subjects and are not"substantively the same" as the Federalrequirements. 49 U.S.C. 5125(b)(1).These covered subjects are:

(A) the designation, description, andclassification of hazardous material;

(B) the packing, repacking, handling,labeling, marking, and placarding ofhazardous material;

(C) the preparation, execution, anduse of shipping documents related tohazardous material and requrementsrespecting the number, contents, andplacement of those documents;

(D) the written notification, recording,and reporting of the umntentionalrelease in transportation of hazardousmaterial; or

(E) the design, manufacturing,fabricating, marking, maintenance,reconditioning, repairing, or testing of a,packaging or a container which isrepresented, marked, certified, or solda qualified for use in transportinghazardous material.

This final rule addresses the design,manufacturing, repairing, and otherrequirements for packages representedas qualified for use in the transportationof hazardous material. Therefore, this

final rule preempts State, local, orIndian tribe requirements that are not"substantively the same" as Federalrequirements on these subjects. Section5125(b)(216f Title 49 U.S.C. providesthat when DOT issues a regulationconcerning any of the covered subjectsafter November 16, 1990, DOT mustdetermine and publish in the FederalRegister the effective date of Federalpreemption. The effective date may notbe earlier than the 90th day followingthe date of issuance of the final rule andno later than two years after the date ofissuance. RSPA has determined that theeffective date of Federal preemption ofthis final rule will be 90 days afterpublication in the Federal Register.

Because RSPA lacks discretion in thisarea, preparation of a federalismassessment is not warranted.

3, Regulatory Flexibility Act

I certify that this final rule will nothave a significant economic impact ona substantial number of small entities.There are nodirect or indirect adverseeconomic impacts for small units ofgovernment, businesses, or otherorganizations.4. Paperwork Reduction Act

This amendment imposes no changesto the information collection andrecordkeeping requirements containedin the June 12, 1989 final rule, whichwere approved by the Office ofManagement and Budget (OMB) underthe provisions of 44 U.S.C. chapter 35and assigned control number 2137-0014..

5. Regulation Identifier Number (IN)

A regulation identifier number (RIN)is assigned to each regulatory actionlisted in the Unified Agenda of FederalRegulations. The Regulatory InformationService Center publishes the UnifiedAgenda in April and October of eachyear. The FIN number contained in theheading of this document can be usedto cross-reference this action with theUnified Agenda.

List of Subjects

49 CFR Part 171

Exports, Hazardous materialstransportation, Hazardous waste,Imports, Incorporation by reference,Reporting and recordkeepingrequirements.

49 CFR Part 173

Hazardous materials transportation,Packaging and containers, Radioactivematerials, Reporting and recordkeepingrequirements, Uranium.

55172 Federal Register / Vol. 59, No. 212 / Thursday November 3, 1994 / Rules and Regulations

49 CFR Part 178 In consideration of the foregoing, title 2. In § 171.7 in paragraph (a)(3) table,

Hazardous materials transportaticn, 49, chapter I of the Code of Federal the first entry for the ASME Code and

Motor vehicles safety, Packaging and Regulations, is amended as set forth the entry for the National Board

containers, Reporting and recordkeeping below: Inspection Code are revised to read as

requirements. PART 171-GENERAL INFORMATION, follows:

49 CFR Part 180 REGULATIONS, AND DEFINITIONS §171.7 Reference material.

Hazardous materials transportation, 1. The authority citation for part 171 (a)Motor carriers, Motor vehicle safety continues to read as follows: (3) Table of material incorporated byPackaging and containers, Reporting Authority: 49 U.S.C. 5101-5127" 49 CFR reference.and recordkeeping requirements. 1.53.

Source and name of material 49 CFR reference

Amencan Society of Mechanical Engineers:ASME Code, Sections II (Parts A and B), V, VIII (Division 1), and, 173.32; 173.306; 173.315; 173.318; 173.420; 178.245; 178.255;

IX of 1992 Edition of American Society of Mechanical Engineers 178.270; 178.271; 178.272; 178.337- 178.338; 178.345; 178.346;Boiler and Pressure Vessel Code and Addenda through Decem- 178.347- 178.348; 179.400; 180.407" 180.417ber 31, 1993.

National Board of Boiler and Pressure Vessel Inspectors:

National Board Inspection Code, A Manual for Boiler and Pressure 180.413Vessel Inspectors, NB-23, 1992 Edition

PART 173-SHIPPERS-GENERALREQUIREMENTS FOR SHIPMENTSAND PACKAGINGS

3. The authority citation for part 173continues to read as follows:

Authority: 49 U.S.C. 5101-5127 49 CFR1.53.

4. In § 173.33, a new paragraph (h) isadded to read as follows:

§ 173.33 Hazardous materials In cargo tankmotor vehicles.

(h) Each liquid or vapor dischargeopening in an MC 330 or MC 331 cargotank and each liquid filling and liquiddischarge line in an MC 338 cargo tankmust be provided with a remotelycontrolled internal self-closing stopvalve, except when an MC 330 or MC331 cargo tank is marked and usedexclusively to transport carbon dioxide,or except when an MC 338 is used totransport argon, carbon dioxide, helium,krypton, neon, nitrogen, and xenon.However, if the cargo tank motor vehiclewas certified before January 1, 1995, thisrequirement is applicable only when anMC 330 or MC 331 cargo tank is usedto transport a flammable liquid,flammable gas, hydrogen chloride(refrigerated liquid), or anhydrousammoma; or when an MC 338 cargotank is used to transport flammableladings.

§ 173.33 [Amended)5. In addition, in § 173.33, in

paragraph (d)(3), a second sentence isadded at the end of the text precedingthe table to read 'The venting capacityrequirements of the original DOT cargotank specification must be metwhenever a pressure relief valve ismodified."

§ 173.225 [Amended]6. In § 173.225, in paragraph (e)(2),

the phrase "MC 310, MC 311, MC 312and DOT 412" is revised to read "MC307 MC 310, MC 311, MC 312, DOT407 and DOT 412"

7 In § 173.315, paragraph (o)(1) andthe first sentence in paragraph (o)(2) arerevised to read as follows:

§173.315 Compressed gases In cargotanks and portable tanks.

(o)(1) Any hose, piping, or tubing used

for loading or unloading that is mountedor carried on the motor vehicle may notbe attached to any valve and must becapped at all ends to prevent the entryof moisture, except at the time ofloading or unloading. Except at the timeof loading and unloading, the pipeconnection of each angle valve must beclosed with a screw plug which ischained or otherwise fastened toprevent misplacement.

(2) Each chlorine cargo tank anglevalve must be tested to be leak free atnot less than 225 psig using dry air or

inert gas before installation andthereafter every, 2 years whenperforming the required periodic retestin § 180.407(c) of this subchapter.

PART 178-SPECIFICATIONS FORPACKAGINGS

8. The authority citation for part 178continues to read as follows:

Authority: 49 U.S.C. 5101-5127 49 CFR1.53.

9. In § 178.337-1, paragraph (e)(2) isamended by revising the last sentence toread as follows:

§ 178.337-1 General requirements.

(e)(2) Insulating material used on

tanks for chlorine must be corkboard orpolyurethane foam, with a minimumthickness of 4 inches, or 2 inchesminimum thickness of ceramic fiber/fiberglass of 4 pounds per cubic footminimum density covered by 2 inchesminimum thickness of fiber.

§ 178.337-1 [Amended)10. In addition, in § 178.337-1, the

following changes are made:a. In paragraph (a)(3), the reference

"173.33(i)" is revised to read "178.337-1(e)(2)" and the reference "173.315(a)Table Note 11" is revised to read"173.315(a) Table':.

Federal Register / Vol. 59, No. 212 / Thursday, November 3, 1994 / Rules and Regulations 55173

b. In paragraph (e)(1), the reference"173.315(a) Table, Notell1" is revised toread "173.315(al Table"

§ 178.337-0 [Amendedi11. In § 178.337-9, paragraph (b)(7)(i)

is removed, and paragraphs (b)(7)(ii)and (b)(7)(iii) are redesignated asparagraphs (b)(7)(i) and (b)(7)(ii).respectively.

12. In § 178.337-11, paragraph (a)(2)introductory text is revised to read asfollows:

§ 178.337-11 Emergency dischargecontrol.

(a)(2) Except for a cargo tank marked

"For carbon dioxide only" each liquidor vapor discharge opening in a cargotank must be equipped with a remotelycontrolled internal self-closing stopvalve. This requirement does not applyto a cargo tank motor vehicle certifiedbefore January 1, 1995, unless intendedfor use to transport a flammable liquid,flammable gas, hydrogen chloride,refrigerated liquid,.or anhydrousammoma. For cargo tanks intended foruse in chlonne service, see paragraph(a)(4) of this section.

13. In § 178.338-9, paragraph (c)(2) isrevised to read as follows.

§ 178.338-0 HoldIng time.

M(c)(2) Same design. The term "same

design" as used in this section meanscargo tanks made to the same designtype. See § 178.320(a](3) for definitionof "design type"

14. In § 178.338-11. in theintroductory text m paragraph (c), thefirst sentence is removed and two newsentences are added to read as follows:

§ 178.338-11 Discharge control devices.

(c) Except for a cargo tank used totransport the following refngeratedliquids: argon, carbon dioxide, helium,krypton, neon, nitrogen, and xenon;each liquid filling and liquid dischargeline must be provided with a remotelycontrolled internal self-closing stopvalve. This requirement does not applyto a cargo tank motor vehicle certifiedbefore January 1, 1995 unless intendedfor use to transport flammableladings. *

15. In § T78.345-1.m paragraph (c);definitions for "Extreme dynamicloading" and "Normal operatingloading" are added, in appropriate

alphabetical order and paragraph (i)(2)is revised to read as follows:

§ 178.345-1 General requirements.

(c

Extreme dynamic loading means themaximum single-acting loading a cargotank may experience during its expectedlife, excluding accident4oadings.

Normal operating loading means theloading a cargo tank may be expected toexperience routinely in operation.

M*(i)(2) The strength of the connecting

structure joinig multiple cargo tanks ina cargo tank motor vehicle must meetthe sttuctural design requirements in§ 178.345-3. Any void within theconnecting structure must be vented tothe atmosphere and have a drain locatedon the bottom centerline. Each drammust be accessible and must be keptopen at all-times. The drain in any voidwithin the connecting structure of acarbon steel, self-supporting cargo tankmay be either a single drain of at least1.0 inch diameter, or two or more drainsof at least 0.5 inch diameter, 6.0 inchesapart, one of which is located on thebottom centerline.

16. In § 178.345-3, paragraphs (b) and(c) are revised to read as follows:

§ 178.345-3 Structural Integrity.

(b) ASME Code design andconstruction. The static design andconstruction of each cargo tank must bein accordance with Section VIII,Division 1 of the ASME Code. The tankdesign must include calculation ofstresses generated by the MAWP theweight of the lading, the weight ofstructures supported by the cargo tankwall and the effect of temperaturegradients resulting from lading andambient temperature extremes. Whendissimilar materials are used, theirthermal coefficients must be used in thecalculation of thermal stresses.

(1) Stress concentrations in tension,bending and torsion which occur atpads, cradles, or other supports must beconsidered in accordance withAppendix G of Section VIII, Division 1of the ASME Code.

(2) Longitudinal compressivebuckling stress for ASME certifiedvessels must be calculated usingparagraph UG-23(b), Section VIII,Division I of the ASME Code. For cargotanks not required to be certified inaccordance with the ASME Code,

compressive buckling stress may becalculated using alternative analysismethods which are accurate andverifiable. When alternative methods areused calculations must include both thestatic loads described in this paragraphand the dynamic loads described inparagraph-(c) of this section.

(c) Shell design. Shell stressesresulting from static or dynamicloadings, or combinations thereof, arenot uniform throughout the cargo tankmotor vehicle. The vertical,longitudinal, and lateral normaloperating loadings can occursimultaneously and must be combined.The vertical, longitudinal and lateralextreme dynamic loadings occurseparately and need not be combined.

(1) Normal operating loadings. Thefollowing procedure addresses stress inthe tank shellresulting from normaloperating loadings. The effective stress(the maximum principal stress at anypoint) must be determined By thefollowing formula:S = 0.5(Sy + S.) ± [0.25(Sy - S,)2 + Ss21

°O5

Where:(i) S = effective stress at any given

point under the combination of staticand normal operating loadings that canoccur at the same time, in psi.

(ii) Sy = circumferential stressgenerated by the MAWP and externalpressure, when applicable, plus statichead, in psi.

(iii) S. = The following netlongitudinal stress generated by thefollowing static and normal: operatingloading conditions, in psi:

(A) The longitudinal stresses resultingfrom the MAWP and external pressure,when applicable, plus static head, incombination with the bending stressgenerated by the static weight of thefully loaded cargo tank, all structuralelements, equipment and appurtenancessupported by the cargo tank wall;

(B) The tensile or compressive stressresulting from normal operatinglongitudinaracceleration ordeceleration. In each case, the forcesapplied must be 0.35 times the verticalreaction at the suspension assembly,applied at the road surface, and astransmitted to the cargo tank wallthrough the suspension assembly ofatrailer during deceleration; or thehorizontal pivot of the tractor orconverter dolly fifth wheel, or thedrawbar hinge on the fixed dolly duringacceleration; or anchoring and supportmembers of a truck during accelerationand deceleration, as applicable. Thevertical reaction must be calculatedbased on the static weight of the fullyloaded cargo tank, all structuralelements, equipment and appurtenances

55174 Federal Register / Vol. 59, No. 212 / Thursday, November 3, 1994 / Rules and Regulations

supported by the cargo tank wall. Thefollowing loadings must be included:

(1) The axial load generated by adecelerative force;

(2) The bending moment generated bya decelerative force;

(3) The axial load generated by anaccelerative force; and

(4) The bending moment generated byan accelerative force; and

(C) The tensile or compressive stressgenerated by the bending momentresulting from normal operating verticalaccelerative force equal to 0.35 times thevertical reaction at the suspensionassembly of a trailer; or the horizontalpivot of the upper coupler (fifth wheel)or turntable; or anchoring and supportmembers of a truck, as applicable. Thevertical reaction must be calculatedbased on the static weight of the fullyloaded cargo tank, all structuralelements, equipment and appurtenancessupported by the cargo tank wall.

(iv) Ss = The following shear stressesgenerated by the following static andnormal operating loading conditions, inpsi:

(A) The static shear stress resultingfrom the vertical reaction at thesuspension assembly of a trailer, and thehorizontal pivot of the upper coupler(fifth wheel) or turntable; or anchoringand support members of a truck, asapplicable. The vertical reaction mustbe calculated based on the static weightof the fully loaded cargo tank, allstructural elements, equipment andappurtenances supported by the cargotank wall;

(B) The vertical shear stress generatedby a normal operating accelerative forceequal to 0.35 times the vertical reactionat the suspension assembly of a trailer;or the horizontal pivot of the uppercoupler (fifth wheel) or turntable; oranchoring and support members of atruck, as applicable. The verticalreaction must be calculated based on thestatic weight of the fully loaded cargotank, all structural elements, equipmentand appurtenances supported by thecargo tank wall;

(C) The lateral shear stress generatedby a normal operating lateralaccelerative force equal to 0.2 times thevertical reaction at each suspensionassembly of a trailer, applied at the roadsurface, and as transmitted to the cargotank wall through the suspensionassembly of a trailer, and the horizontalpivot of the upper coupler (fifth wheel)or turntable;.or anchoring and supportmembers of a truck, as applicable. Thevertical reaction must be calculatedbased on the static weight of the fullyloaded cargo tank, all structuralelements, equipment and appurtenancessupported by the cargo tank wall; and

(D) The torsional shear stressgenerated by the same lateral forces asdescribed in paragraph (c)(1)(iv)(C) ofthis section.

(2) Extreme dynamic loadings. Thefollowing procedure addresses stress inthe tank shell resulting from extremedynamic loadings. The effective stress(the maximum principal stress at anypoint) must be determined by thefollowing formula:S = 0.5(S, + S.) ± [0.25(S, S.)2 + Ss2]0 .5

Where:(i) S = effective stress at any given

point under a combination of static andextreme dynamic loadings that canoccur at the same time, in psi.

(ii) Sy = circumferential stressgenerated by MAWP and externalpressure, when applicable, plus statichead, in psi.

(iii) S. = the following netlongitudinal stress generated by thefollowing static and extreme dynamicloading conditions, in psi:

(A) The longitudinal stresses resultingfrom the MAWP and external pressure,when applicable, plus static head, incombination with the bending stressgenerated by the static weight of thefully loaded cargo tank, all structuralelements, equipment and appurtenancessupported by the tank wall;

(B) The tensile or compressive stressresulting from extreme longitudinalacceleration or deceleration. In eachcase the forces applied must be 0.7times the vertical reaction at thesuspension assembly, applied at theroad surface, and as transmitted to thecargo tank wall through the suspensionassembly of a trailer duringdeceleration; or the horizontal pivot ofthe tractor or converter dolly fifthwheel, or the drawbar hinge on the fixeddolly during acceleration; or theanchoring and support members of atruck during acceleration anddeceleration, as applicable. The verticalreaction must be calculated based on thestatic weight of the fully loaded cargotank, all structural elements, equipmentand appurtenances supported by thecargo tank wall. The following loadingsmust be included:

(1) The axial load generated by adecelerative force;

(2) The bending moment generated bya decelerative force;

(3) The axial load generated by anaccelerative force; and

(4) The bending moment generated byan accelerative force; and

(C) The tensile or compressive stressgenerated by the bending momentresulting from an extreme verticalaccelerative force equal to 0.7 times thevertical reaction at the suspension

assembly of a trailer, and the horizontalpivot of the upper coupler (fifth wheel)or turntable; or the anchoring andsupport members of a truck, asapplicable. The vertical reaction mustbe calculated based on the static weightof the fully loaded cargo tank, allstructural elements, equipment andappurtenances supported by the cargotank wall.

(iv) Ss = The following shear stressesgenerated by static and extremedynamic loading conditions, in psi:

(A) The static shear stress resultingfrom the vertical reaction at thesuspension assembly of a trailer, and thehorizontal pivot of the upper coupler(fifth wheel) or turntable; or anchoringand support members of a truck, asapplicable. The vertical reaction mustbe calculated based on the static weightof the fully loaded cargo tank, allstructural elements, equipment andappurtenances supported by the cargotank wall;

(B) The vertical shear stress generatedby an extreme vertical accelerative forceequal to 0.7 times the vertical reactionat the suspension assembly of a trailer,and the horizontal pivot of the uppercoupler (fifth wheel) or turntable; oranchoring and support members of atruck, as applicable. The verticalreaction must be calculated based on thestatic weight of the fully loaded cargotank, all structural elements, equipmentand appurtenances supported by thecargo tank wall;

(C) The lateral shear stress generatedby an extreme lateral accelerative forceequal to 0.4 times the vertical reactionat the suspension assembly of a trailer,applied at the road surface, and astransmitted to the cargo tank wall-thrbugh the suspension assembly of atrailer, and the horizontal pivot of theupper coupler (fifth wheel) or turntable;or anchoring and support members of atruck, as applicable. The verticalreaction must be calculated based on thestatic weight of the fully loaded cargotank, all structural elements, equipmentand appurtenances supported by thecargo tank wall; and

(D) The torsional shear stressgenerated by the same lateral forces asdescribed in paragraph (c)(2)(iv)(C) ofthis section.

§ 178.345-3 [Amended]17 In addition, in § 178.345-3, the

following changes are made:a. In paragraph (a)(1), the,phrase at.

the beginning of the sentence "Except asprovided in paragraph (d) of thissection, the" is removed and replacedwith the word "The"

No. 212 / Thursday, November 3, 1994 / Rules and Regulations55174 Federal Register / Vol. 59,

No. 212 / Thursday, November 3, 1994 / Rules and Regulations 55175

b. In paragraph (a)(3), the wording"paragraphs (b), (c), and (d) of thissection" is revised to read "paragraphs(b) and (c) of this section" each place itappears.

c. Paragraph (d) is removed.d. Paragraphs (e) through (g) are

redesignated as paragraphs (d) through(1), and m redesignated paragraph (d)the wording "cargo tank wall" is revisedto read "cargo tank shell and heads"

18. In § 178.345-5, a new paragraph(f) is added to read as follows:

§ 178.345--5 Manhole assemblies.

{f) All fittings and devices-mountedon a manhole cover, coming in contactwith the lading, must withstand thesame static internal fluid pressure andcontain the same permanent compliancemarkings as that required for themanhole cover. The fitting or devicemanufacturer shall verify complianceusing the same test procedure andfrequency of testing as specified in§ 178.345-5(b).

§ 178.345-4 6Amended)19. In § 178.345-6, in paragraphs (a)

and (b), the second sentence of eachparagraph is revised to read "The designcalculations of the support elementsmust include the stresses indicated in§ 178.345-3(b) and as generated by theloads described m § 178.345-3(c)."

20. In § 178.345-8, paragraphs (a)(3),(b) introductory text, (b)(1), (c)introductory text, (c)(1), and (d)(3) arerevised; and a new paragraph (e) isadded to read as follows:

§ 178.345-8 Accident damage protection.

(a)(3) Accident damage protection

devices attached to the wall of a cargotank must be able to withstand ordeflect away from the cargo tank theloads specified in this section. Theymust be designed, constructed andinstalled so as to maximize thedistribution of loads to the tank walland to minimize the possibility ofadversely affecting the lading retentionintegrity of the cargo tank. Accidentinduced stresses resulting from theappropriate accident damage protectiondevice requirements in combinationwith the stresses from the tank operatingat the MAWP may not result in a tankwall stress greater than the ultimatestrength of the material of constructionusing a safety factor of 1.3. Deformationof the protection device is acceptableprovided the devices being protected arenot damaged when loads specified inthis section are applied.

(b) Each outlet, projection or pipinglocated in the lower 1/3 of the tankcircumference (or cross sectionperimeter for non-circular tanks) thatcould be damaged in an accident thatmay result in the loss of lading must beprotected by a bottom damageprotection device, except as provided byparagraph (a)(1) of this section and§ 173.33(e) of this subchapter. Outlets,projections and piping may be groupedor clustered together and protected by asingle protection device.

(1) Any bottom damage protectiondevice must be able to withstand a forceof 155,000 pounds (based on theultimate strength of the material) fromthe front, side, or rear, uniformlydistributed over each surface of thedevice, over an area not to exceed 6square feet, and a width not to exceed6 feet. Suspension components andstructural mounting members may beused to provide all, or part, of thisprotection. The device must extend noless than 6 inches beyond anycomponent that may contain lading intransit.

(c) Each closure for openings,including but not limited to themanhole, filling or inspection openings,and each valve, fitting, pressure reliefdevice, vapor recovery stop valve orlading retaining fitting located in theupper 2/3 of a cargo tank circumference(or cross section perimeter for non-circular tanks) must be protected bybeing located within or betweenadjacent rollover damage protectiondevices, or by being 125 percent of thestrength that would be provided by theotherwise required damage protectiondevice.

(1) A rollover damage protectiondevice on a cargo tank motor vehiclemust be designed and installed towithstand loads equal to twice theweight of the loaded cargo tank motorvehicle applied as follows: normal tothe tank shell (perpendicular to the tanksurface); and tangential (perpendicularto the normal load) from any direction.The stresses shall not exceed theultimate strength of the material ofconstruction. These design loads may beconsidered to be uniformly distributedand independently applied. If more thanone rollover protection device is used,each device must be capable of carryingits proportionate share of the requiredloads and in each case at least one-fourth the total tangential load. Thedesign must be proven capable ofcarrying the required loads bycalculations, tests or a combination oftests and calculations.

(d)(3) The structure of the rear-end

protection device and its attachment tothe vehicle must be designed to satisfythe conditions specified in paragraph(d)(1) of this section when subjected toan impact of the cargo tank motorvehicle at rated payload, at adeceleration of 2 "g" Such impact mustbe considered as being uniformlyapplied in the horizontal plane at anangle of 10 degrees or less to thelongitudinal axis of the vehicle.

{e) Longitudinal decelerationprotection. In order to account forstresses due to longitudinal impact in anaccident, the tank shell and heads mustbe able to withstand the load resultingfrom the design pressure in combinationwith the dynamic pressure resultingfrom a longitudinal deceleration of 2"g" For this loading condition, theallowable stress value used may notexceed the ultimate strength of thematerial of construction using a safetyfactor of 1.3. Performance testing,analytical methods, or a combinationthereof, may be used to prove thiscapability provided the methods areaccurate and verifiable. For cargo tankswith internal baffles, the decelerativeforce may be reduced by 0.25 "g" foreach baffle assembly but in no case maythe total reduction in decelerative forceexceed 1.0 "g"

21. In 178.345-10, paragraphs (b)(3)(i)and (ii),are revised to read as follows:

§ 178.345-10 Pressure relief.

(b,)(3)(i) Each pressure relief device must be

able to withstand dynamic pressuresurge reaching 30 psig above the designset pressure and sustained above the setpressure for at least 60 millisecondswith a total volume of liquid releasednot exceeding one gallon before therelief device recloses to a leak-tightcondition. This requirement must bemet regardless of vehicle orientation.This capability must be demonstratedby testing. An acceptable test procedureis outlined in TTMA RP No. 81-"Performance of Spring Loaded PressureRelief Valves on MC 306, MC 307 andMC 312 Tanks," May 24, 1989 edition.

(ii) After August 31, 1995, eachpressure relief device must be able towithstand a dynamic pressure surgereaching 30 psig above the design setpressure and sustained above the designset pressure for at least 60 millisecondswith a total volume of liquid releasednot exceeding one liter before the reliefvalve recloses to a leak-tight conditionThis requirement must be metregardless of vehicle orientation. This

Federal Register / Vol. 59,

55176 Federal Register / Vol. 59, No. 212 1 Thursday November 3, 1994 / Rules and Regulations

capability must be demonstrated bytesting. "TMA RP No. 81, cited inparagraph (b)(3)(i) of this section, is anacceptable test procedure.

§ 178.345-13 [Amended]22. In § 178.345-13, a heading is

added to paragraph (c)'to read "Leakagetest."

§ 178.345-14 [Amended]23. In § 178.345-14, in paragraph (d),

the following changes are made:a. The paragraph heading "Multi-

cargo ,tank cargo lank motor vehicle" isrevised to read "Multi-tank cargo tankmotor vehicle"

b. At the end of the second sentence,the phrase "unless all of the cargo tanksare identical" is revised to read "unlessall cargo tanks are made by the samemanufacturer with the same materials,manufactured thickness, mnimmumthickness and to the samespecification"

24. In § 178.345-15, a sentence isadded in the beginning of paragraph(b)(2) and a new paragraph (e) is addedto read as follows:

§ 178.345-15 Certification.

(~b)(2) For each ASME tank, a tank

manufacturer's data report as requiredby:the ASME Code. '

(e) Specification shortages. If a cargotank is manufactured which does notmeet all applicable. specificationrequirements, thereby requiringsubsequent manufacturing involving theinstallation of additional components,parts, appurtenances or accessories, the

J cargo tank manufacturer may affix thename plate and specification plate, asrequired by § 178.345-14 (b) and (c),without the original date of certificationstamped on the specification plate. Themanufacturer shall state thespecification requirements not compliedwith on the manufacturer'sCertificate ofCompliance. When 'the cargo tank isbrought into full compliance with theapplicable specification, the RegisteredInspector shall stamp the date ofcompliance on 'the specification plate.The Registered Inspector shall issue aCertificate of Compliance stating detailsof the particular operations performedon the cargo tank, and 'the date andperson '(manufacturer, camer, or repairorganization) accomplishing thecompliance.

25. In § 178.346-1, new paragraphs(d)(9) and (10) are added to read asfollows:

§ 178.346-1 General requirements.

(d)(9) Single full fillet lap joints without

plug welds may be used for arc or gaswelded longitudinal seams withoutradiographic examination under thefollowing conditions:

(i) For a truck-mounted cargo tank, nomore than two such joints may be usedon the top half of the tank and no morethan two jomts may be used on thebottom half. They may not be locatedfarther from the top and bottomcenterline than 16 percent of the shell'scircumference.

(ii) For a self-supporting cargo tank,no more than two such joints may beused on the top of the tank. They maynot be located farther from the topcenterline than 12.5 percent of theshell's circumference.

(iii) Compliance test. Two testspecimens of the material to be used inthe manufacture of a cargo tank must -betested to failure in tension. The testspecimens must be of the samethicknesses and joint configuration asthe cargo tank, and joined by the samewelding procedures. The test specimensmay represent all the tanks that aremade of the same materials and weldingprocedures. have the same jointconfiguration, and are made in the samefacility within 6 months after the testsare completed. Before welding, the fit-up of the jointson the test specimensmust represent production conditionsthat would result in the least jointstrength. Evidence of joint fit-up andtest results must be retained at themanufacturers' facility.

(iv) Weld joint efficiency. The lowervalue of stress at failure attained in thetwo tensile test specimens shall be usedto compute the efficiency of the joint asfollows: Determine the failure ratio bydividing the stress at failure by themechanical properties of the adjacentmetal; this value, when multiplied by0.75, is the design weld joint efficiency.

(10) The requirements of paragraphUW-9(d), of Section VIII, Division 1,ASME Code -do not apply.

§ 178.346-. [Amended]26. In § 178.346-2, the paragraph (a)

designation is removed; the phrase"DOT 406 cargo tanks" is revised toread "DOT 406 cargo tank motorvehicles" and in Table II, the heading"Rated capacity (gallons)" in the firstcolumn is revised to read "Cargo tankmotor vehicle rated capacity (gallons)"

27 In § 178.346-10, the word "and"at the end of paragraph (b)(1) isremoved, the period -at the end ofparagraph (b)(2) is removed and "" and"is added in its place, a new paragraph

(b)(3) is added and paragraphs (c)( 1)and (d)(1) are revised to read as follows:

§ 178.346-10 Pressure relief.

(b)(3) Notwithstanding the requirements

in § 178.345-10(b), after August 31,1996, each pressure relief valve must beable to withstand a dynamic pressuresurge reaching 30 psig above the designset pressure and sustained above the setpressure for at least 60 millisecondswith a total volume of liquid releasednot exceeding one liter before the reliefvalve recloses to a leak-tight condition.This requirement must be metregardless of 'vehicle orientation. Thiscapability must be demonstrated bytesting. TTMA RP No. 81, cited at§ 178.345-10(b)(3)(i), is an acceptabletest procedure.

(c)(1) Notwithstanding the requirements

in § 178.345-10(d), the set pressure of.each primary relief valve must be notless than 110 percent of the MAWP or3.3 psig, whichever is greater, and notmore than 138 percent of the MAWPThe valve must close at not less than theMAWP and remain closed at lowerpressures.

(d) *(1) Notwithstanding the requirements

in § 178.345-10 (e) and (g), the primarypressure relief valve must have aventing capacity of at least 6;000 SCFH,rated at not greater than 125 percent ofthe tank test pressure and not greaterthan 3 psig above the MAWP Theventing capacity required in § 178.345-10(e) may be rated at these samepressures.

28. In § 178.346-13, paragraph (c) isrevised to read as follows:

§ 178.346-13 Pressure and leakage tests.

(c) Leakage test. Cargo tanks equippedwith vapor collection equipment may beleakage tested in accordance with theEnvironmental Protection Agency's"Method 27-Determination of VaporTightness of Gasoline Delivery TankUsing Pressure-Vacuum Test," as setforth in 40 CFR Part 60, Appendix A.Acceptance critena are found at 40 CFR60.501 and 60.601.

PART 180--CONTINUINGQUAUFICATION AND MAINTENANCEOF PACKAGINGS

29. The authority citation for part 180continues to read as follows:

Authority: 49U.S.C. 5101-5127 49 CFR1.53.

No. 212 / Thursday November 3, 1994 / Rules and Regulations 55177

30. In § 180.403, a new definition"Replacement of a barrel" is added, inthe appropnate alphabetical order, toread as follows:

§ 180.403 Definitions.

Replacement of a barrel means toreplace the existiig tank on a motorvehicle chassis with an unused (new)tank. For the definition of tank, see§ 178.345-1(c), § 178.337-1, or§ 178.338-1 of this subchapter, asapplicable.

31. In § 180.405, paragraph (h) isrevised to read as follows:

§ 180.405 Qualification of cargo tanks.

(h) Pressure relief system. Properlyfunctioning reclosmg pressure reliefvalves and frangible or fusible ventsneed not be replaced. However,replacement of reclosing pressure reliefvalves on MC-specifiqation cargo tanksis authorized subject to the followingrequirements:

(1) Until August 31, 1998, the ownerof a cargo tank may replace a reclosingpressure relief device with a devicewhich is in compliance with therequirements for pressure relief devices

in effect at the time the cargo tankspecification became superseded. If thepressure relief device is installed as anintegral part of a manhole coverassembly the manhole cover mustcomply with the requirements ofparagraph (g) of this section.

(2) After August 31, 1998,replacement for any reclosing pressurerelief valve must be capable of reseatingto a leak-tight condition after a pressuresurge, and the volume of lading releasedmay not exceed one liter. Specificperformance requirements for thesepressure relief valves are set forth in§ 178.345-10(b)(3) of this subchapter.

(3) As provided in paragraph (c)(2) ofthis section, the owner of a cargo tankmay elect to modify reclosing pressurerelief devices to more recent cargo tankspecifications. However, replacementdevices constructed to the requirementsof § 178.345-10 of this subchapter mustprovide the minimum venting capacityrequired by the original specification towhich the cargo tank was designed andconstructed.

§ 180.405 [Amended]32. In addition, in § 180.405 the

following changes are made:

a. In paragraph (fl(1)(iii), the phrase"prescribed in § 178.345-3 of thespecification" is revised to read"prescribed in § 178.345-3 of thissubchapter or the specification"

b. In paragraph (0(4) introductorytext, the phrase "and an outlet-isequipped" is revised to read "andexcept that an outlet is equipped"

33. In § 180.407 in the table inparagraph (c), immediately under thesubheading "Leakage Test" in the firstcolumn, the following entry is addedand the wording "All cargo tanks exceptMC 338" is revised to read "All othercargo tanks except MC 338"' paragraph(e)(1) is revised; paragraph (h)(2) isrevised; paragraphs (i)(5) through (i)(7)are redesignated as paragraphs (i)(6)through (i)(8), respectively- the word"and" is removed at the end ofparagraph (i)(4)(viii); the period at theend of paragraph (i)(4)(ix) is removedand "" and" is added in its place; andnew paragraphs (i)(4)(x) and (i)(5) areadded, to read as follows:

§ 180.407 Requirements for test andInspection of specification cargo tanks.

(c)

COMPLIANCE DATES-INSPECTIONS AND RETESTS UNDER § 180.407(c)

Date by which first Interval pe-Test or inspection (cargo tank specification, configuration, and service) test must be corn- nod after

pleted (see note 1) first test

[Add]-

Leakage Test:MC 330 and MC 331 cargo tanks in chlonne service ................................................................................... Sept. 1, 1991 ......... 2 years

Note 1: If a cargo tank is sublect to an applicAble inspection or test requirement under the regulations in effect on December 30, 1990, and thedue date (as specified by a requirement in effect on December 30, 1990) for completing the required inspection or test occurs before the compli-ance date listed in Table I, the-earlier date applies.

(e) (1) When the cargo tank isnot equipped with a manhole orinspection opening, or the cargo tankdesign precludes an internal inspection,the tank shall be hydrostatically orpneumatically tested in accordance with180.407(c) and (g).

(h)(2) Cargo tanks equipped with vapor

collection equipment may be leakagetested in accordance with theEnvironmental Protection Agency's"Method 27-Determination of VaporTightness of Gasoline Delivery TankUsing Pressure-Vacuum Test," as setforth in 40 CFR Part 60, Appendix A.

Acceptance criteria are found at 40 CFR60.501 and 60.601.

G)(4)(x) Connecting structures joining

multiple cargo tanks of carbon steel ina self-supporting cargo tank motorvehicle.

(5) Minimum thicknesses for MC 300,MC 301, MC 302, MC 303, MC 304, MC305, MC 306, MC 307 MC 310, MC 311,and MC 312 cargo tanks are shown.inthe tables below. The columns headed"Specified Manufactured Thickness"tabulate the minimum values requiredfor new construction, generally found; inTables I and II of each specification. "In-

Service Minimum Thicknesses" arebased on 90 percent of themanufactured thickness as specified inthe DOT specification, rounded to threeplaces.

Federal Register / Vol. 59,

55178 Federal Register / Vol. 59, No. 212 / Thursday, November 3, 1994 / Rules and Regulations

TABLE .- MINIMUM THICKNESS FORMC 300, MC 303, MC 304, MC306, MC 307 MC 310, MC' 311AND MC ,312 SPECIFICATION CARGOTANKS CONSTRUCTED OF STEELAND STEEL ALLOYS

NominalSpecified manufac- decimal In-servicetured thickness (US equiva- minimumgue othinces '( lent for thicknessgauge or Inches) reference (inches)

'(inches)

19 ............................. .0.0418 0.03818 .............................. 0.0478 0.04317 ................. 0.0538 0.04816 .............................. 0.0598 0.05415 .............................. 0.0673 0.06114 .............................. . 0.0747 0.06713 ............................. 0.0897 0.08112 .............................. 0.1046 0.09411 .............................. 0.1196 0.10810 .............................. 0.1345 0.1219 ................................ 0.1495 0.1358 ............................... 0.1644 0.1487 ................................ 0.1793 0.1613/16 ........................... 0.1875 0.1691/4 ............................. 0.2500 0.2255/16 ........................... 0.3125 0.2813/8 ............................. . 0.3750 0.338

TABLE -1I.-MINIMUM THICKNESS FORMC 301,. MC 302, MC 304, MC305, MC 306, MC 307 MC 311AND MC 312 SPECIFICATION CARGOTANKS CONSTRUCTED OF ALUMINUMAND ALUMINUM ALLOYS

In-serviceSpecified manufactured thickness minimum

(inches) thickness(inches)

0.078 ............................................. 0.0700.087 ............................................. 0.0780.096 ............................................. 0.0860.109 ............................................. 0.0980.130 ........................ 0.1170.141 ............................................. 0.1270.151 ............................................. 0.1360.172 ............................................. 0.1550.173 ............................................. 0.1560.194 ............................................. 0.1750.216 ............................................. 0.1940.237 ............................................. 0.2130.270 ............................................. 0.2430.360 ............................................. 0.3240.450 ............................................. 0.4050.540 ............................................. 0.486

§ 180.407 [Amended]34. In addition, in § 180.407 the

following changes are made:a. In paragraph (d)(1)(ii), the wording

"and the cargo tank is not equipped" isrevised to read "or the cargo tank is notequipped"

b. hiparagraph (e)(2)(ii), the wording"as specified § 180.407(f)." is revised toread "as specified in § 180.407(f)."

c. Paragraph (e)(4) is removed, andparagraph (e)(5) is redesignated asparagraph (e)(4).

d. In paragraph (g)(1)(iv), the word"minimum" is removed.

35. Section 180.413 is revised to readas follows:

§ 180.413 Repair, modification, stretching,or rebarrelling of cargo tanks.

(a) General. For purposes of thissection, "stretching" is not considered a"modification" and "rebarrelling" is notconsidered a "repair." Any repair,modification, stretching, or rebarrellingof a cargo tank must be performed inconformance with the requirements ofthis section.

(b) Repair--1) Non-ASME 'Codestamped cargo tanks. Any workinvolving repair on an MC 300, MC 301,MC 302, MC 303, MC 304, MC 305, MC306, MC 307 MC 310, MC 311, or MC312 cargo tank that is not ASME Codestamped must be performed by:

(i) A cargo tank manufacturer holdinga valid ASME Certificate ofAuthorization for the use of the ASME"U" stamp and registered with DOT or

(ii) A repair facility holding a validNational Board Certificate ofAuthorization for the use of the NationalBoard "R" stamp and registered withDOT

(2) ASME Code stamped cargo tanks.Any work involving repair on anyASME Code stamped cargo tank must beperformed by a repair facility holding avalid National Board Certificate ofAuthorization for the use of the NationalBoard "R" stamp and registered iaccordance with subpart F of part 107of subchapter B of this chapter.

(3) The following provisions apply tocargo tank repairs:

(i) DOT 406, DOT 407 and DOT 412cargo tanks must-be repaired inaccordance with the specificationrequirements in effect either.at the timeof manufacture or at the time of repair;

(ii) MC 300, MC 301, MC 302, MC303, MC 305, and MC 306 cargo tanksmust berepaired in accordance witheither the original specification or withthe DOT 406 specification in effect atthe time of repair;

(iii) MC 304 and MC 307 cargo tanksmust be repaired in accordance witheither the onginal specification or withthe DOT 407 specification in effect atthe time of repair;

(iv) MC 310, MC 311, and MC 312cargo tanks must be repaired inaccordance with either the originalspecification or with the 'DOT 412specification in effect at the time of therepair;

(v) MC 338 cargo tanks-must berepaired in accordance with the

specification requirements in effecteither at the time of manufacture -or atthe time of repair, and

(vi) MC 330 and MC 331 cargo tanksmust be repaired in accordance with therepair procedures described in CGATechnical Bulletin TB-2 and theNational Board Inspection Code-Provisions for Repair of PressureVessels. Each cargo tank having cracksor other defects requiring weldedrepairs must meet all of therequirements of § 178.337-16 of thissubchapter (in effect at the time of therepair), except that postweld heattreatment after minor weld repairs is notrequired. When any repair is made ofdefects revealed by the wet fluorescentmagnetic particle inspection, includingthose by grinding, the affected area ofthe cargo tank must again be examinedby the wet fluorescent magnetic particlemethod after hydrostatic testing toassure that all defects have beenremoved.

(4) Prior to any repair work, the cargotank must be emptied of any hazardousmaterial lading. Cargo tanks containingflammable or toxic lading must bepurged.

(5) Any repair of a cargo tankinvolving welding on the shell or headmust be certified by a RegisteredInspector. Any repair of an ASME Code"U" stamped cargo tank must be inaccordance with the National BoardInspection Code.

(6) The suitability of any repairaffecting the structural integrity of thecargo tank must be determined bytesting as prescribed in § 180.407

(c) Maintenance or replacement ofpiping, valves, hoses or fittings. In theevent of repair, maintenance orreplacement, any piping, valve, orfitting must be properly installed inaccordance with the provisions of theapplicable specification before the cargotank is returned to hazardous materialsservice. After maintenance orreplacement which does not involvewelding on the cargo tank wall, therepaired piping, valves or fittings, thereplaced segment of the piping must beleak, tested. After repair or replacementof piping, valves or fittings whichinvolves welding on the cargo tank wall.the entire cargo tank, including therepaired'or replaced piping, valve orfitting, must be pressure tested inaccordance with the applicablespecification. Hoses permanentlyattached to the cargo tank must be testedeither before or after installation.

(d) Modification, stretching, orrebarrelling. Modification, stretching orrebarrelling of a cargo tank mustconform to the following provisions:

Federal Regmter / Vol. 59, No. 212 / Thursday November 3, 1994 / Rules and Regulations 55179

(1) Non-ASME Code stamped cargotanks. If the modification, stretching, orrebarrelling will result in a design typechange, then it must be approved by aDesign Certifying Engineer. Any workinvolving modification, stretching, orrebarrelling on an MC 300, MC 301, MC302, MC 303, MC 304, MC 305, MC 306,MC 307 MC 310, MC 311, or MC 312cargo tank that is not ASME stampedmust be performed by:

(i) A cargo tank manufacturer holdinga valid ASME Certificate ofAuthorization for the use of the ASME"U" stamp and registered with DOT, or

(ii) A repair facility holding a validNational Board Certificate ofAuthorization for the use of the NationalBoard "R" stamp and registered withDOT

(2) ASME Code stamped cargo tanks.The modification, stretching, orrebarrelling on any ASME Codestamped cargo tank must be performedby a repair facility holding a validNational Board Certificate ofAuthorization for the use of the NationalBoard "R" stamp and registered inaccordance with subpart F of part 107of subchapter B of this chapter. If themodification, stretching, or rebarrellingwill result in a design type change, thenit must be approved by a DesignCertifying Engineer.

(3) All new material and equipment,and equipment affected by themodification, stretching or rebarrellingmust conform with requirements of thespecification in effect at the time of suchwork. In addition, the modification,stretching or rebarrelling must beperformed such that the cargo tank, asmodified, stretched or rebarrelled, meetsthe applicable structural integrityrequirements (§ 178.337-3, § 178.338-3,or § 178.345-3 of this subchapter) of thespecification in effect at the time of suchwork. The work must conform to therequirements of the applicablespecification as follows:

(i) For specification MC 300, MC 301,MC 302, MC 303, MC 305 and MC 306cargo tanks, the provisions of eitherspecification MC 306 or DOT 406 untilAugust 31, 1995 and, thereafter tospecification DOT 406 only-

(ii) For specification MC 304 and MC307 cargo tanks, the provisions of eitherspecification MC 307 or DOT 407 untilAugust 31, 1995 and, thereafter tospecification DOT 407 only;

(iii) For specification MC 310, MC311. and MC 312 cargo tanks, theprovisions of either specification MC312 or DOT 412 until'August 31, 1995and, thereafter to specification DOT 412only; and

(iv) For specification MC 330 cargotanks, the provisions of specificationMC 331.

(4) The person performing themodification, stretching, or rebarrellingmust:

(i) Have knowledge of the originaldesign concept, particularly withrespect to structural design analysis,material and welding procedures;

(ii) Assure compliance with therebuilt cargo tank's structural integrity,venting, and accident damage protectionrequirements;

(iii) Assure compliance with allapplicable Federal Motor Carrier SafetyRegulations for any newly installedsafety equipment;

(iv) Perform all retest procedures oneach cargo tank in accordance with theapplicable specification and § 180.407-

(v) Change the existing specificationplate to reflect the cargo tank asmodified, stretched or rebarrelled. Thismust include the name of the: persondoing the work, his DOT registrationnumber, date, retest information, etc. Asupplemental specification plate may beinstalled immediately adjacent to theexisting plate(s), or the existingspecification plate may be removed andreplaced with a new plate; and

(vi) On a variable specification cargotank, install a supplemental or newvariable specification plate, and replacethe specification listed on the original-specification plate with the words "seevariable specification plate"

(5) The design of the modified,stretched, or rebarrelled cargo tank mustbe approved by a Design CertifyingEngineer registered in accordance withsubpart F of part 107 of subchapter B ofthis chapter, The Design CertifyingEngineer must certify that the modified,stretched, or rebarrelled cargo tankmeets the structural integrityrequirements of the applicablespecification. The person performingthe modifying, stretching or rebarrellingand a Registered Inspector must certifythat the cargo tank is in compliancewith this section and the applicablespecification by issuing a supplementalmanufacturer's certificate. Theregistration number of the RegisteredInspector and the person performing themodification, stretching, or rebarrellingmust be entered on the certificate. Whena cargo tank is rebarrelled, it must bedesigned, constructed and certified inaccordance with a cargo tankspecification currently authorized forconstruction in Part 178 of tbissubchapter.

(6) If the mounting of the cargo tankon the cargo tank motor vehicle involveswelding on the cargo tank head or shell,

then the mounting must be performed asfollows:

(i) Non-ASME Code stamped cargotanks. For a non-ASME: Code stampedcargo tank-

(A) By a cargo tank manufacturerholding an ASME "U" stamp, registeredwith DOT and under the direction of aDesign Certifying Engineer; or

(B) By a repair facility holding anASME "U" stamp or a National Board"R" stamp, registered with DOT, andunder the direction of a DesignCertifying Engineer.

(ii) ASME Code stamped cargo tank.For an ASME Code stamped cargo tank,by a repair facility holding a NationalBoard "R" stamp, registered inaccordance with subpart F of part 107of subchapter B of this chapter, andapproved by a Design CertifyingEngineer.

(7) If the mounting of a cargo tank ona cargo tank motor vehicle does notinvolve welding on the cargo tank heador shell, or a change or modification ofthe methods of attachment, then themounting shall be in accordance withthe original specification or with thespecification in effect at the time of themounting. If the mounting involves anychange or modification of the methodsof attachment, then the mounting mustbe approved by a Design CertifyingEngineer.

(8) Prior to any modification,stretching, or rebarrelling a cargo tankmust be emptied of any hazardousmaterial lading. Cargo.tanks containingflammable or toxic lading must bepurged.

(9) Any modification, stretching, orrebarrelling on the cargo tank involvingwelding on the shell or head must becertified by a Registered Inspector. Anyrepair of an ASME Code "U" stampedcargo tank must be in accordance withthe National Board Inspection Code.

(10) The suitability of modification,stretching, or rebarrelling affecting the.structural integrity of the cargo tankmust be determined by testing asprescribed for new manufacture in theapplicable specification.

(e) Records. Each owner of a cargotank must retain at its principal place of.business all records of repair,modification, stretching, or rebarrellingmade to each tank during the time thetank is in service and for one yearthereafter. Copies of these records mu-stbe retained by a motor carrier, who iqnot the owner of the cargo tank, at itsprincipal place of business during theperiod the tank is in the carrier'sservice. The seller of a cargo tank shallprovide the purchaser acopy of thecargo tank Certificate of Compliance,and all repair, inspection and test

55180 Federal Register / Vol. 59, No. 212 / Thursday November 3, 1994 / Rules and Regulations

reports upon sale as an MC or DOTcargo tank.

Issued in Washington, DC on October 21,1994, under authority delegated in 49 CFRPart 1.D.K. Sharma,Administrator, Research and SpecialPrograms Administration.IFR Doc. 94-26625 Filed 10-28-94; 1:21 pm]BILUNG CODE 4910-60-P