3 - Shock Absorbers, Energy Absorbers, Rigid Struts

8/9/2019 3 - Shock Absorbers, Energy Absorbers, Rigid Struts

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SHOCK ABSORBERS, ENERGY ABSORBERS,RIGID STRUTS

PRODUCTGROUP

3


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78

9

01

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93.0

SHOCK ABSORBERS, ENERGY ABSORBERS (E-BARS),RIGID STRUTS, DYNAMIC PIPE CLAMPS

Field of application________________________________________________3.1

Main products ____________________________________________________3.2

Recommendations for use __________________________________________3.3

Shock absorbers, type 30, type 31 __________________________________3.4

Installation extensions, type 33 _____________________________________3.7

Weld-on brackets, type 35__________________________________________3.8

Operational performance, type 30, type 31____________________________3.9

Permissible stress factors, type 30, type 31__________________________3.10

Mode of operation, type 30, type 31________________________________3.11

Shock absorbers, design characteristics _____________________________3.13

Shock absorbers, function tests ____________________________________3.14

Installation instructions, type 30, type 31____________________________3.15

Maintenance recommendations type 30, type 31 _____________________3.17

Dynamic pipe clamps, type 36, type 37 _____________________________3.19

Dynamic pipe clamps overview, OD 33.7 - OD 914.4 __________________3.21

Dynamic pipe clamps, installation instructions________________________3.31

Energy absorbers (E-Bar), type 32 __________________________________3.33

Rigid struts, type 39______________________________________________3.37Pipe whip restraints ______________________________________________3.41

CONTENTS PAGE

3

PRODUCT GROUP 3
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Product group 3 componentsPipe supports specially designed for thepurpose are necessary to absorb and trans-fer loads from dynamic events. With ProductGroup 3, LISEGA provides a comprehensivesystem whereby all fields of application arecovered by the corresponding ideal compo-nent. This enables users to exploit optimumconcepts.

The LISEGA Product Group 3 includes thefollowing main products:

shock absorbers, types 30 and 31 energy absorbers (E-Bars), type 32 rigid struts, type 39

A comprehensive selection of connection pos-sibilities is available for the correct installa-tion of the main products:

installation extensions, type 33 weld-on brackets, type 35 dynamic pipe clamps, types 36 and 37

In accordance with the LISEGA modular system, the connecting parts are designed

to be compatible and are subject to uniformcalculation criteria. A generally applicabletable of permissible loads can be found onpage 0.5 of the Technical Specifications.

The fundamental calculation procedurescomply with international regulations andstandards and are certified by practical typeand suitability tests.Design Report Summariesin accordancewith ASME III NFare available.

Dynamic eventsWhenever unplanned dynamic events occur,LISEGA Product Group 3 supports have thejob of protecting the piping or other com-ponents affected from any damage.

Undesirable abrupt movement of the com-ponents in the system can be caused by:

A Internal excitation, such as:

pressure shocks from valve operation water hammer boiler events pipe breakage

B External excitation, such as:

wind load seismic events aircraft impact explosions

Components affected can be:

piping pumps valve assemblies pressure vessels steam generators

To avoid unacceptable ten-sion and moments in thepiping system, unplanneddisplacement in piping or other plant components must be eliminated. However, ther-mal movement must not behindered in any way!

PRODUCT GROUP 3FIELD OF APPLICATION

3.1

Diagram of an operating basis earthquake (O.B.E.)


5/443.2

3Shock absorbers, type 30, 31The use of shock absorbers (snubbers) ispreferred in thermally operating pipingsystems. In a dynamic event, shock absor-bers instantaneously form a practically rigidrestraint between the protected componentand the structure. Resulting dynamic energycan at once be absorbed and harmlesslytransferred.

Through the special function of the shockabsorbers, thermal displacements during nor-mal operation remain unhindered.

Energy absorbers, type 32

If only slight operational movement is to beexpected at the load application point, thenas a rule energy absorbers can be used.These components allow a small amount of movement, which is limited by an adjustablegap in the end positions. The componentsaffected are protected from overload because,due to the design, the dynamic energy intro-duced is transformed into deformation energy.

Rigid struts, type 39If no operational movement is to be expec-ted, e.g. at so-called zero positions, thenrigid struts are used. They form rigidrestraints from attachment point to attach-ment point and do not allow axial move-ment. However, as they have angular bear-ings, limited angular movement is permitted.

PRODUCT GROUP 3MAIN PRODUCTS

stroke

free stroke(adjustable)

rigid


6/443.3

PRODUCT GROUP 3RECOMMENDATIONS FOR USE

Product Group 3components are dynamically stressed. In their use, the following pointsmust be observed for effective functioning:

1. Where the design of dynamically fixedpoints is concerned, the stiffness of thesupporting system as a whole , i.e. of allcomponents in the support chain, must beconsidered.

2. In the selection of unit sizes, the total of all loadings avising must be taken intoaccount.

3. For given loads it must be made clear,

beyond any doubt, which level of design load(H, HZ, HS, and/or Level A,B,C,D) the datacorresponds to. The table of permissible loadson page 0.5 of the Technical Specificationsmust be observed.

4. The stroke length of shock absorbersshould not be fully exploited. An overtravelsafety margin of 10mm at each end of thesnubber should be maintained.

5. When arranging the components, sufficient lateral freedom should be allowed so thatthere is no jamming at connection lugs.

6. When shock absorbers are arranged inparallel, it is recommended that load re-serves be considered. Instead of 50%, ineach case it is recommended that bothshock absorbers be designed to take 70%of the total calculation load.

7. The installation drawings should clearlyindicate how much freedom of angulationmay be required by the components.

8. Any necessary torque values for threadedconnections in the structural attachmentsshould be indicated.

9. Before commissioning the plant, all sup-port points should again be visually inspec-ted.

10. The LISEGA instructions for commissioning and inspection, as well as the maintenancerecommendations, are to be observed.

Special design of dynamic restraint clamp

Type 37

Type 30

Type 33

Type 35

Type 35

Type 39

Type 36

Type 35

Type 39

Type 36 Type 30

Type 35

Type 39

Type 37 Type 39

Type 35

Type 30

Type 35

Type 35

Type 30

Type 36

Type 36

Type 35

Type 33

Type 30Type 39

Type 35

Type 39

Type 35


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LISEGA shock absorbers have stood the test of time in practical applications for over three decades, and thereby proven their outstanding reliability. Extensive operationalexperience has, through constant further development, led to a matured product, uni-

versally respected and leading worldwide.

Access to shock absorbers after installation isgenerally difficult and, because of possibledanger from radiation when installed innuclear power plants, involves stringentsafety regulations for personnel. The highestdemands are therefore made on reliable andmaintenance-free continuous service.

For the reliable operational safety of shockabsorbers, the quality of the following criticalcomponents, together with the functional prin-ciple and whole design, is a decisive factor:

sealing systems piston and rod guides hydraulic fluid sliding surfaces corrosion-resistant interiors control valve system

SHOCK ABSORBERSTYPE 30, 31

The most frequent causes offailure in shock absor-bers are prematurewear and tear andcorrosion. For thisreason LISEGAshock absorbersare manufacuredfrom non-corrodingmaterials and any form of metal to metal contactis precluded by the use of special guide bands.

At LISEGA, the sealing system, guidings andhydraulic fluid are certified through reliable

qualification procedures to give at least 23years trouble free operation in nuclear power stations under normal operating conditions.

The following qualities have led to the recog-nized superiority of LISEGA shock absorbers:

non-corroding materials special sealing systems vibration proof guide systems pressurized self-contained hydraulic system

dynamic function exchangeable control valves (Type 31) 23 years approved maintenance-free

operation 40 year lifespan certified by ASME - NCA 3800

certified by TV qualificationtesting

3


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SHOCK ABSORBERSTYPE 30

3.5

See Technical Specifications, table Permissibleloads on page 0.5 and Welding the weld-on bracketson page 3.16

Usual design load for earthquakes and similar loadevents. See also Technical Specifications, page 0.5

Emin = piston rod retractedEmax = piston rod extended

To bridge greater installed lengths,extensions, type 33 (page 3.7) can be used.

Order details:Shock absorbertype 30 .. ..With two weld-on bracketstype 35 .. ..,

Marking:

Type 30 18 16 to 30 03 12Series producedStandard design

Available from stock or from running production.Only non-corroding materi-als are used. Connectionlugs (material = P250GH,C45E+QT) attached viathreaded connections aregalvanized.

3.5

When exchanging other products, the connectiondimensions such as pin diameters and lug lengths canbe made to fit the attachments already built into thestructure.

Units with longer strokes can be provided onrequest.

conn. lug

ball bush

name plate

piston rod cover

travel indicator

sight glass

Type

30 18 1630 38 1630 39 1630 42 1630 43 1630 52 1330 53 1330 62 1630 63 1630 72 1630 73 1630 82 1630 83 1630 92 1330 93 1330 02 1230 03 12

Nom. load(kN)

Stroke D d3 Emin F R SGWeight

(kg)Emax

388

18184646

100100200200350350550550

10001000

EmergencyLevel C

4.010.610.623.923.961.061.0141141267267472472735735

13351335

100100200150300150300150300150300150300150300150300

5470708585

135135170170200200270270300300390390

101212151520203030505060607070

100100

220315410395545445595535685615765730880760910935

1085

320415610545845595895685985765

1065880

1180910

121010851385

18505058586565

100100130130165165165165240240

15202022.522.53030454560607575

105105145145

910101212161622223535444449497070

1.94.35.78.3

12.020.029.037.051.061.078.0

122.0147.0175.0207.0390.0460.0


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3Shock absorbersType 31 98 16 to 31 58 16

Type 31 shock absorbers arespecially designed to deal withlarge loads.They are mainly used in nuc-lear power stations to protectsteam generators and largepumps. Due to the restrictedspace in such areas, their dimensions are generally de-signed to suit the given condi-tions.The table on this page there-

fore serves as general orienta-tion during initial planning.Housing and connection lugsare high tensile stainless steelcastings.

See Technical Specifications, table Permissibleloads on page 0.5 and Welding the weld-on bracketson page 3.16

Usual design load for earthquakes and similar loadevents. See also Technical Specifications, page 0.5

Order details:Shock absorber, type 31 .. ..With two weld-on bracketstype 35 .. ..Marking:

SHOCK ABSORBERSTYPE 31

Emin = piston rod retractedEmax = piston rod extended

L max at 80C

Design of travel indicator for travel range 8(100mm stroke) .

LISEGA shock absorbers type 31are fitted with exchangeable valves

for on site testing

conn. lugball bush travel indicator

name plateremovable valves fluid level indicator

weld-on bracket

Type31 98 1631 99 1631 08 1631 09 1631 28 1631 38 1631 48 1631 58 16

Weight(kg)Stroke D d3Emin F G H R SG

Emax Lmax.

EmergencyLevel C

Nom. load(kN)

550550

100010002000300040005000

735735

133513352660400053206650

100200100200100100100100

240240330330440540580630

7070

100100120140160180

620735765880870

102010501140

720935865

1080970

112011501240

9595

120120160190205230

9090

110110155180200220

310310385385450620585670

115145145200150100255205

105105140140160200245290

494970708590

105105

152181285338648968

13001750

E

L


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INSTALLATION EXTENSIONSTYPE 33

Installation extensionstype 33 18 18 to 33 03 12

Type 33 extensions are usedto bridge larger installationlengths, thus avoiding struc-tural adjustments on site.

Connection to the shockabsorber or energy absorber is made at the cylinder base. Standard threadedconnections allow thesimple substitution of exten-sions for standard connec-

tion lugs. The same appliesfor special connections,helpful when exchangingunits made by other manu-facturers, because this wayexisting structural con-nec-tions can remain (see page3.8).

Material:P355T1

Order details:Installation extensiontype 33 .. ..L= mm

for hydr. shock absorber

Piston at midposition Installation dimensions greater than E max on loadreduction possible. Shorter L dimensions can be supplied,but then without adjustment possibility.

min. thread engagement

extension tube

countering ring lug with ball bushing

Type

33 18 1833 38 1833 39 1833 42 1833 43 1833 52 1333 53 1333 62 1833 63 18

33 72 1833 73 18

33 82 18

33 83 18

33 92 1333 93 1333 02 1233 03 12

+ per100mm

Nom. load(kN)

388

18184646

100100

200200

350

350

550550

10001000

Shockabs.

strokeA d3 D

max Emax

L minEmin

L 37.5min

L 37.5max

205195195205205220220270270

315315390

1071390886440440555555

520445230763395950600

14401115

1855135510701760

88514552200190018801555

100100200150300150300150300

150300

150

300

150300150300

240315460412635455680510735

560785

640

865

670895770995

101212151520203030

5050

60

60

7070

100100

253030353548486464

838390

10090

100115115160160

445510655617840675900780

1005

875110010301711125517511110133513251550

760760690

117510301405128019501850

2415214017102400175023202870279526502550

0.450.600.600.900.901.501.502.302.30

5.005.00

10.0045.0010.0036.0033.0033.0090.0090.00

0.390.550.550.750.750.720.721.901.90

3.603.603.404.703.404.705.505.509.509.50

Weight (kg)

L 37.5


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3WELD-ON BRACKETSTYPE 35Weld-on bracketsType 35 19 13 to 35 20 19

This unit is used as a con-nection for shock absorberstype 30 and 31, energy ab-sorbers type 32 and rigidstruts type 39 (also for types16, 20, 27), and formsthe structural attachment.

The brackets are made fromeasily weldable carbon steelS355J2G3 and the precisionfit stainless steel connec-

ting pins.Weld-on brackets type 35can be supplied with bolt-on base plates on request.

See Technical Specificationstable Permissible loads on page0.5 and Welding of weld-onbrackets on page 3.16

Fit: bore H7, pin f8.

Order details: Weld-on bracket, type 35 .. ..

Flange for connecting to existing extension

Special lugs

Special lugs with length adjustment

Standard extension

It is a well known fact that most earlier generation shock absorbers do not fulfillcurrent demands and specifications.The result is failure, and huge maintenancecosts. Considerable savings can be made byreplacing these units with LISEGA shock or energy absorbers (E-bars).

So that connections already existing on sitecan still be used, a range of special connec-tions is available.

SPECIAL CONNECTIONS

Nom. load(kN) A B C d3 E F RL

Weight(kg)

348

1846

100

200350550

10002000

Type

35 19 1335 29 1335 39 1335 49 1335 59 1935 69 19

35 79 1935 89 1935 99 1135 09 1335 20 19

252530355490

110150180390520

323237435479

100130230310320

121212131523

2534405865

101012152030

506070

100120

303034405075

90115155212245

9.59.5

10.512.516.522.5

35.545507287

424246526595

115160220305320

131315182745

557580

100135

0.20.20.30.51.03.7

7.917.041.0

132.0215.0


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stroke200mm

SHOCK ABSORBERS TYPE 30, 31OPERATIONAL PERFORMANCE

3.9

travel range 8 100 mm, travel range 2 150 mm,travel range 9 200 mm

Rt = Room temperature. At ambient temperature of 150 C (shortduration, max. 1h) piston rod travel may be increased by up to 50% due toreduced fluid viscosity.

Measured at a constant piston speed of appr. 0.3 mm/s. Breakawayforce is kept at less than 1.5 of given values.

If required, Sa can be increased to 0.5 mm by conforming to other performance data (KTA 3205.3 ).

travel range 8, travel range 3 travel range 8 travel range 92, 9 (stroke 300 ) (stroke 100 ) (stroke 200 )

6mm 8mm 10mm 12mm

Type30 Type31

Piston rod travel Sb at F N, Rt and 1-35 HzPiston rod travel Sa (lost motion)Lockup velocity at Rt

Frictional resistance

0.5 mm2-6 mm/s

Bypass velocity at F N and Rt 0.2-2 mm/s0.01F N or 200N 0.015F N or 300N

at FN 20 kN at FN20 kN

0.01F N

Force travel diagram Force and travel amplitudes

Operational performanceUnder dynamic load, LISEGA shock ab-sorbers, depending on the operationalload spectrum, offer a constant, predic-table, functional performance.

Specified function valuesAs standard, LISEGA shock absorbersmaintain the function values listed be-low. The values are based on cyclic or dynamic load.

The data conforms to international stan-dards and practical requirements.Adherence to the specifications isproven and recorded by acceptance testsat the factory. By means of designadaptations, special parameters can becomplied with on request.

Actual performance in relation to normal load and travel range

stroke= 300mm

Force F

rigidity

piston travel S

Ffaulted

-Ffaulted

Femergency

-Femergency

FN

-FN


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absorbers endure these loads whilemaintaining their functional integrity.

The special guide systems of the shockabsorbers make them largely resistantto permanent cyclic operating loads.This is confirmed by proven practicalexperience.

It has to be considered that the rangeof possible influential parameters suchas frequencies, amplitudes, oscillationshapes, impact directions, mono- andmultiaxial effects, as well as possibleoverlapping, permit no uniform definitionof continuous operational vibration.

Operational Stress FactorsLISEGA hydraulic shock absorbers aredesigned as standard for the operationalloads listed below.

The specified values have been con-firmed by German TV qualificationtests. Other values can be agreed uponin exceptional cases by design adap-tations.

SHOCK ABSORBERS, TYPE 30, 31PERMISSIBLE STRESS FACTORS 3

Resistance to fatigueProof of operational durability is basedon the following accumulated loadspectrum:

Normal load FN . . . . . .Load cycles10 % . . . . . . . . . . . . .2,000,00050 % . . . . . . . . . . . . . .100,00080 % . . . . . . . . . . . . . . .20,000

100 % (Level A/B) . . . . . . . . .10,000133 % (Level C) . . . . . . . . . . .100172 % (LeveI D) . . . . . . . . . . . .10

short term max.1h/temp. cyclemax.40h per year

at 10-150C

max.150C

accumulated

continuous

short term

permanent max.80C

max.150C

100%

X=1

0.5-1 bar

5 bar excess pressure

105 J/ kg ( 107 rad)

Loading due to environmentaltemperature

Relative humidity

Wet steam atmosphere

Energy dose

Ambient pressure

The values cited above refer to a shockabsorber incl. seals and hydraulic fluid.Special values for the fluid only are:

Pour point

Flash point

Ignition point

300C

500C

-50C

Hydraulic fluid(silicone oil)

The number of cycles corresponds toestimated maximum dynamic stressesfrom diverse load events within a periodof forty years. It also complies with thetest program requirements of the suit-ability tests conducted by the GermanTV. The results prove that the shock

Test area for shock absorbers at the Zeven factory, Germany

Testing shock absorbers, type 31Test load 4500kN

Optimum testing is achieved by using computer controlled test equipment


14/443.11

MODE OF FUNCTION

Dynamic event In the event of a sudden shock, an instan-taneous, secure and almost rigid connectionis produced between the supported com-ponent and the fixed point on the structure.The resulting dynamic loads are at onceconducted into the structural connection anddissipated without any harmful consequences.

Normal operational movements of piping andother components remain however unhindered.

Moments of force can often change directionat random within the framework of complex oscillation spectra. The response frequencyrange for LISEGA shock absorbers is 0.5 -100 Hz.

FUNCTION

Control valvesThe function of LISEGA hydraulic shock ab-sorbers type 30 is controlled by the main con-trol valve (B), axially mounted within thehydraulic piston (A).During the piston movement ( 2mm/s) thevalve is kept open by spring pressure, and

hydraulic fluid flows freely from one side of the piston to the other. During rapid pistonmovement (approx. 2mm/s) above thespeed limit, the resulting fluid flow pressureon the valve plate closes the main valve.The flow of the hydraulic fluid is stoppedand movement blocked. The compressibilityof the fluid cushion has a softening effecton the restriction of the piston. This pre-vents damaging load spikes.For movement in the compressive direction,the compensating valve (D) closes almostsynchronously with the main valve.

If the pressure on the closed valve subsides,e.g. through reversal of the direction of move-ment, the main control valve opens automa-tically when the fluid force falls short of thespring force.

BypassTo prevent the valves from jamming in theblocking position, they are fitted with abypass system.

Function scheme of a shock absorber, type 30

A B C D

SHOCK ABSORBERSMODE OF OPERATION


15/443.12

This allows limited piston movement under continuing load and ensures safe opening of the valves by rapid equalization of pressurein both cylinder chambers. The compensa-ting valve works synchronously with themain valve in the same way.

Reservoir For both variable piston rod positions as wellas for changes in hydraulic fluid volumecaused by temperature changes, volume com-pensation takes place through a coaxiallymounted reservoir (C). The link between thereservoir and main cylinder is regulated bythe compensating valve (D).

Large bore shock absorbers type 31The function of the LISEGA shock absorber type 31 is fundamentally the same as for type

30.The special dimensions, however, require adifferent design arrangement of the reservoir (C). The valve assembly also differs.

The valves (B) themselves operate similarlyto those in type 30. The circulation of thefluid is also blocked by closure of the corres-ponding valve in each respective direction of movement. This happens whenever a flow-

Function scheme of a shock absorber type 31

A

C

B

speed limit is exceeded. Because the valvesare directly linked to the reservoir, no specialcompensating valve is needed.

Recurrent testing To facilitate routine maintenance, the controlvalve system is designed for removal with theshock absorber still in place. The valves canthen simply be replaced in the event of arecurrent test by a previously qualified set of valves. A special shut-off device is used toprevent loss of oil. The original valves canthen be remotely tested in a surrogate snub-ber and made ready for use again.

3


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SHOCK ABSORBERSDESIGN CHARACTERISTICS

3.13

Design characteristicsThe shock absorbers are closed systemswith no external threaded pressureconnections. Individual parts of the unitare assembled without welding bymeans of precision fits and threadedconnections and secured mechanically(see Fig. 3).

For protection against corrosion,LISE-GA shock absorbers are made exclusi-vely from non-corroding materials. Theconnections are made of galvanizedcarbon steel.The guides on piston rods and pistons

are made from a special wear-resistantnon-metallic material (see Fig. 2).

The fluid reservoir is sealed from theatmosphere by a preset piston, so thatslight overpressure in the hydraulicsystem constantly maintains a slightpresetting of the seals.

The control valves are decisive for thedynamic operation of the shock absorber.To achieve high operational accuracy,the valve parameters have been opti-mized by extensive testing and specialcalculation models.

SealsThe sealing systems play a vital role inthe long term function of a hydraulicshock absorber. Together with the hyd-raulic fluid and guide bands, the sealsform part of the non-metallic compo-nents of the shock absorber and aretherefore subject to natural ageing andwear. The most important requisite for a lasting sealing effect is the selectionof the right sealing material. A goodmemory for shape retention (compres-sion set) or lowest possible relaxation of tension is thereby an absolute essential.

For optimum exploitation of materialcharacteristics, the shape of the sealsand the design of their locations arealso important.

The optimum combination of thefollowing factors is decisive forfunctional efficiency:

temperature resistance radiation resistance abrasion resistance, especially

at high frequency vibration good memory for shape retention good dry running qualities limited diffusion tendency into the

metal surfaces minimal stick/slip drag effect

The material which best meets these requ-irements is a special compound on thebasis of the fluor elastomer VITON.To exploit the special characteristics tothe fullest extent, the following criteriamust also be considered:

special design shapes backing compound materials optimum mixture consistency optimally balanced hardness precision in gliding surfaces design of locations for defined

presetting of seals

Commercially available seals in shockabsorbers do not fulfill these require-ments, and as experience has shown,lead to premature failure. For LISEGAshock absorbers, a specific sealing sys-tem was developed as early as 1984 incooperation with a major seal manufact-urer. Since then, these seals havedemonstrated their worth in practicalapplication.

Alongside other successful qualificationprocedures through artificial ageing andfatigue tests, a qualification test proced-ure was carried out on LISEGA shockabsorbers in 1992 by order of a major European nuclear utility. The tests cer-tified a maintenance free service life of at least 23 years in nuclear power plants under normal operating condi-tions.

Control indicatorsThe piston position of the shock ab-sorbers can be read from all sides bychecking the scale rings on the body of the cylinder. The sturdy stainless steelshroud connected to the piston rod pro-tects it from mechanical damage, dirtand heat and also serves as an indicator.

The fluid level of the reservoir is indi-cated by the position of the reservoir piston. A sight glass can be used for checking the minimum level in type 30.Type 31 has a marked indicator rodattached to the base of the externalreservoir.

For details of design and materials,see Technical Specifications.

(Fig. 1 )

(Fig. 2 )

(Fig. 3 )


17/443.14

3SHOCK ABSORBERSFUNCTION TESTSLISEGA applies a test procedure using the verylatest technology. The test benches operate asdynamic hydro pulse units, with either force-controlled or travel-controlled excitation asdesired.The frequency bands range from0.5 - 30Hz and the test loads from0.5 - 5000 kN. Altogether, seven test benchesof various sizes are available for LISEGA indifferent factories.At customers request, they are frequently usedon site as mobile units. Several test bencheshave been supplied to different countries to

The particularly stringent requirements within thenuclear industry demandflawless proof concerning the functional parametersfor shock absorbers.This applies both to thefirst acceptance test as wellas to recurrent testing.

Acceptance certificate with test diagrams

Frictional resistance (kN)

Quasistatic functional tests

Drag velocity (mm/s)Lock up velocity (mm/s)Bypass velocity (mm/s)

Load after valve activation (kN)Load at bypass velocity (kN)/bleed rate

Dynamic functional tests(Load and travel amplitudes)

displacement (mm)

compression / tension loads (kN)

Load/travel diagram

be used on site by local plant personnel forrecurrent testing.Variable test programs permit shock absorber tests for all makes.

All LISEGA test benches are regularly inspected,certified and calibrated by authorized bodies.


18/443.15

Shock absorbers are pre-cision-made, safety-relatedcomponents. Corresponding care must therefore be takenwhen handling them.For the flawless functioning of the shock absorbers it isessential that the following instructions are observed.

Transport and storageShock absorbers and related componentsshould be stored in closed rooms and pro-tected from dirt and damage. Transportationmust therefore be carried out with great care.LISEGA recommends that the shock absorbersremain in their original packing until just bef-ore installation. Any damage during shipment,off loading, on site transportation or instal-lation must be reported to the manufacturer immediately.

Delivery conditionShock absorbers are supplied as fully oper-ational units, complete with hydraulic fluid,

ready for service. The connecting lugs for type 30 are connected at one end with thebase, at the other with the piston rod andsecured by locking bolts.For type 31 the bottom end lug and cylinder base form a unit.

LISEGA shock absorbers are made entirelyfrom non-corroding materials, so they needno additional surface treatment. The threadedconnecting lugs are electrogalvanized andwhite chromatized.

Type 35 weld-on brackets are supplied sepa-rately, including fitted pins. Their surface hasa protective coating of weldable primer.

For transportation, type 30 shock absorbersare supplied packaged individually in pur-pose made boxes with pistons fully retrac-ted. Type 31 are fixed on special woodenskids.

For these unit sizes, the actual installationdimensions are preset at the factory.

InstallationShock absorbers must be inspected for da-mage before installation. Also, the connec-ting lugs must be checked for tight fits. Thestruc-tural attachments on site and weld-onbrackets must be completely welded. Thearrange-ment of the weld-on brackets mustbe such that the maximum angular displace-ment takes place in the direction of thegreatest thermal expansion in service.Lateral displacement is limited to a maxi-mum of 6. Any twisting of the weld-on

brackets against each other should be pre-vented because of the limitation on move-ment resulting from this.

All welding at the connections or in their vicinity should be completed before installingthe shock absorbers.

For installation, type 30 shock absorbers mustbe set at the required installation length (theconnection pin to connection pin dimension)by extending the piston rods. This must bedone slowly, smoothly and below the lockupvelocity to avoid blocking the shock absor-ber. Smaller types can be extended by hand.The weight of the larger shock absorbers canbe exploited to help extend them by hangingthe unit to the connecting lug of the pistonrod.

The shock absorbers can be installed in prac-tically any conceivable position. The pistonrod should be connected to the heat con-ducting component to dissipate, via the pro-tective shroud, any heat from radiation.

The installation position of the absorbersshould be so selected as to offer easy accessto the sight glass for fluid inspection duringservice checks.

Type 30

weld-on bracket

conn. lug

name platepiston rod cover

travel indicator

sight glass

SHOCK ABSORBERS TYPE 30, 31INSTALLATION INSTRUCTIONS


19/44

~

3.16

3Welding the weld-on bracketsThe following procedure is recommended for the welding of weld-on brackets:

The minimum weld seam thickness a for type 35 weld-on brackets is dependent onthe angular displacement and . A per-missible stress of 90N/mm 2 at load caseLevel A formed the basis of the calculation.

If the angular displacement increases to90, the permissible loads are reduced byapproximately 15% at a constant weld seamthickness (a min at = 45 ).For permissible loads, see load table in

Technical Specifications, page 0.5

Welding procedure1. Remove pins from weld-on brackets2. Preheat weld-on brackets, from

type 35 79 19 onwards, to 100C3. Use base electrodes4. Welding should be performed in layers

to avoid welding distortion.(For sequence, see diagram)

5. Allow bracket to cool to 100Cafter each welding layer

Type 31

=15 = 6

=30 = 6

=45 = 6

The connections to the various attachmentstructures must be form-fit for load actu-ation. All threaded connections in the flux of force must be tightened with sufficienttorque.

If, after installation, any welding on theattachment structure is performed near theinstalled shock absorber, care must be takenthat no welding current strays through thebody of the snubber.

After installing the complete system, it isrecommended that each unit be inspectedfor the following:

A. Correct fitting of form-fit connections for load actuation (locking screws on the connec-ting lugs, secure pins, threaded connec-tions).

B. All installation points must be checkedfor adequate freedom of movement duringthermal expansion. Care must be taken toallow the connecting lugs to move freely inthe connection brackets and care also takento prevent the piston from reaching the endposition.

For the piston position, a safety zone of10mm at each end of the cylinder stroke isrecommended. The position can be read fromthe travel scale.

Before commissioning the plant, a full visualinspection of all shock absorbers and instal-lation situations is recommended.

weld-on bracketconn. lugname plateball bushing

travel indicator fluid level indicator

removable valves

a a aType

35 19 1335 29 1335 39 1335 49 13

35 59 1935 69 1935 79 1935 89 1935 99 1135 09 1335 20 19

3.03.03.03.0

5.57.5

10.514.515.014.023.0

3.03.03.04.0

7.09.5

13.518.020.017.0

3.03.03.05.0

8.011.015.521.023.019.0

~


20/44

For normal operating conditions shock absor-bers are designed to function for the entire40 year life of a plant. The seals and hyd-raulic fluid should be changed at least onceduring this period, at the latest after 20years.

However, under certain conditions (extremestresses) shock absorbers can experience pre-mature ageing and increased mechanical wear.Preventive maintenance is recommended inorder to make sure the shock absorbers re-main fully operational and reliable. This main-tenance is the responsibility of the plant ope-rators.

Measures

1. Regular inspection -visual inspection, once per year

2. Extended inspection -function tests, 12 years aftercommissioning at the latest.

ImplementationInspection and maintenance work should becarried out by specially trained personnel.LISEGA servicing specialists can do this if required. For dynamic function tests, qualifiedtest benches which can also be brought tothe plant are available.

1. Regular inspectionRegular inspection should involve a visualinspection carried out once a year on all unitsinstalled. The first inspection should takeplace immediately before commissioning.

During the regular inspection, not only theshock absorbers must be inspected, but alsothe environmental conditions and installationsituation. The check list should include thefollowing points:

all units to be inspected, notinginstallation position

planned operational connectiondisplacements

special environmental or operatingconditions.

any maintenance work previouslycarried out.

3.17

Mobile computer controlled LISEGAtest bench in a Belgian nuclear

power plant

SHOCK ABSORBERSMAINTENANCE RECOMMENDATIONS

Shock absorbers are com-ponents of great safety-related significance for aplant. They offer protec-tion to the piping systemand other componentsagainst dynamic over-loading due to unplannedload events. As these areunpredictable, the comp-lete functional safety of theshock absorbers must beguaranteed at all times.


21/443.18

The following should be checked at theinstalled position:

Conformity of name plate data withcheck list.

Correct form fitting of all connections forload actuation

Correct freedom of movement of shockabsorber during operating displacements

Position of main piston rod as regardssufficient stroke, including travel reserve(min. 10 mm).

Exterior condition of shock absorber forany damage or leakage.

Surrounding area for possible signs ofunusual operating conditions,e.g. increased temperature

Fluid indicator level

As long as the reservoir piston cannot beseen through the sight glass there is suffi-

cient fluid in the reservoir. If the piston isvisible, it must be assumed that fluid hasbeen lost.

Observations and findings are to be recordedon the check list and if required, recommen-dations for corrective action made.

2. Extended inspectionAn extended inspection is carried out after 12 years of operation, whereby a number of installed shock absorbers (min. 2 units per type) are subjected to an additional functiontest. After successful testing, the shock ab-sorbers can be reinstalled for further service.In the event of deviations in performance,the shock absorber in question should bedismantled and the function-related parts in-spected. The plant operators are responsiblefor taking and documenting any correctivemeasures.

The scope of testing and the selection of shock absorbers should be agreed on by therelevant plant department and the serviceengineer responsible. Special considerationis to be given to various stress factors(temperature, radiation, loads, operationalvibrations).

The timing and scope of the next ExtendedInspection is to be decided on the basis of inspection results recorded.

After approximately 20 years of operation atthe latest, it is recommended that the hydraulicfluid and seals are replaced in all shock

absorbers. Following this work, carried outby trained personnel using original LISEGAspare parts, and after successful functiontesting, the shock absorbers can be usedagain for a further 20 years.

3

Examples of shock absorber installation in nuclear plants


22/44

DYNAMIC PIPE CLAMPSTYPE 36, 37

3.19

Instability caused by twisted clamps of thefrictional grip type (fig. 1) is especially dan-gerous. Because of the unavoidable creepcharacteristics of preset metals a lasting fric-tional grip cannot be maintained at hightemperatures by way of simple bolt preset-ting. Even oversize boltings do not solve theproblem, because on corresponding preset-ting they would cause impermissible contrac-tion of the pipe (pipe squeezer).

A typical fault is too soft a clamp design(fig. 2), where the necessary stiffness isnot attained.

Care should be taken that the connec-tions on the pipe clamps fit snugly.

So that no constraints arise, sufficientroom for lateral movement ondisplacement in the piping systemmust be guaranteed.

Prevention of twisting through shear lugsTo prevent twisting, LISEGA recommends onprinciple the use of shear lugs with dynamicpipe clamps (fig. 3, 5, 6). This way, definedand verifiable behavior is ensured.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

The lugs maintain the position of the pipeclamps in the expected direction of force andare not subjected to any significant load(fig. 5). Even in the load case, no significantlateral stresses are produced, as the frictionforces on the contact surface of the pipeunder load provide a secure grip.

Because of the slight forces to be absorbed,welding stress can be kept to a minimum,despite the small dimensions of the shear lugs. Generally, they are kept below 35% of the yield strength, or creep stress limit for load condition H, according to the permis-sible values in ASME / DIN codes.

Frictional grip with the help of disc springsIf the welding of lugs is not possible for anyfundamental reason, LISEGA offers dynamicpipe clamps fitted with disc springs (fig. 4).Via correspondingly dimensioned sets of springs, a lasting torque for permanent frictiongrip can be produced.

Fig. 5

Fig. 6

Lug dimensions

Force distribution in a dynamic pipe

clamp with shear lug connection

lug

tube

frictionlug

friction

frict ion t ube= 0.1...0.4 (friction value)

N = Catalog dimension F less 1mm

1.5 x N

0 - 2

m m

Catalog dimension B1add. 2mm

In the sphere of dynamicsupports, the design of pipe clamps is often not carried out with sufficient care. In spite of impeccablemain support units (shock absorbers, rigid struts andenergy absorbers), thefunctioning of the wholeconstruction can be adver-sely affected by faulty pipe clamps.

O D

OD


23/44

If no special arrangement is ordered, thebracket connection is so fitted that the mainangulation range runs along the axis of thepipe. For type 37, the weld-on bracket is tobe ordered separately.

3LISEGA standard designTo provide the ideal solution for all areas of application and at the same time achievethe most favorable performance weightratios, LISEGA offers four standard designs.

Dynamic pipe clamps as hanger clampsThe given permissible loads have been cal-culated for dynamic operation with shockabsorbers / rigid struts in accordance with thedynamic load spectra shown on page 3.10.

In special cases the dynamic clamps are fittedas hanger clamps, under permanent staticload. In this case, the given permissible loadshave to be reduced as per the following table:

Special designsIn some cases, special designs can be a use-ful alternative to pipe clamps types 36 and37. Especially in cases of parallel and angu-lated arrangements, standardized designand calculation methods have proven their worth.

SelectionThe selection tables are divided according topipe diameters. Via the temperature rangesand the permissible loads, the type designa-tion for the appropriate clamp is found. After that, the installation dimensions are to bechecked using the drawing. Special attentionmust be given to the lug connections of shockabsorbers, energy absorbers or rigid struts.If the standard pin connection d1 does notfit, another appropriate weld-on bracket (seepage 3.8) can be provided.

Type 36 .. .1/2/3

Type 37. .. 1/2/3/4/5/6

Type 36 .. .4/5

Type 37 .. .7/8/9

3.20

pipe clamp permissibletemperature material permanent

tensile stress

until350 C S235JRG2 / S355J2G3100%450 C 16Mo3 90%500 C 16Mo3 55%510 C 13CrMo4-5 65%530 C 13CrMo4-5 55%560 C 13CrMo4-5 45%

This calculation applies to creep strengths dep. on timein the range of 200,000h at temperatures 450C.

Special clamp for angular arrangement

Dynamic axial pipe clamp with shock absorbers

Type 36 Type 37


24/443.21

Calculation of interimvalues: linear interpolation.

The connecting load grouphas to be stated in the order.On selection of a lower loadgroup than stated in the table,the E dim. of the clamp is re-duced in accordance with theE dim. of the weld-on bracket(see page 3.8 ).

Lug dimensions: F less 1mm;B1 plus 2mm (see page 3.19).

Type 36 .. .1

DYNAMIC PIPE CLAMPSELECTION TABLE OD 33.7 - OD 108.0

C Emax Ad1 B B1 kgFmax.Load gr.250 350 450 500 510 530 560100

4.0 4.0 4.04.0 4.0

4.0 3.9 2.9

101010

110155160

757575

505050

202020

999

222

Type36 03 1136 03 2136 03 31

permissible laod (kN)


permissible load (kN)

C Emax Ad1 B B1 kgFmax.Load gr.250 350 450 500 510 530 560100Type

36 05 1136 05 2136 05 31



36 06 1136 06 2136 06 31



36 07 1136 07 2136 07 31


OD 33.7 (ND 25 )

OD 42.4 (ND 32 )

OD 48.3 (ND 40 )

OD 60.3 (ND 50 )

OD 73.0 (ND 65 )


36 08 1136 08 2136 08 31



36 09 1136 09 2136 09 31



36 10 1136 10 2136 10 31


OD 76.1 (ND 65 )

OD 88.9 (ND 80 )

OD 108.0 (ND 100 )

Type36 04 1136 04 2136 04 31

8.0

8.0

16

15

15

23

32 29 2418 15

13 11 8.1

201515

205265270

165165165

505050

353530

111111

544

4.96.55.5

20 1918 15

14 11 8.3

201515

185230235

146146146

505050

303030

111111

544

3.84.54.3

14 138.0 7.7

7.0 5.8 4.3

151212

160210215

125125125

505050

252525

999

433

2.22.72.7

14 128.0 7.6

6.9 5.8 4.2

151212

160210215

120120120

505050

252525

999

433

2.22.72.6

14 118.0 8.0

7.2 6.1 4.4

151212

150190195

110110110

505050

252525

999

433

1.92.22.2

8.0 7.46.5 5.1

4.0 4.0 2.9

121210

130175175

909090

505050

202020

999

332

1.21.51.4

8.0 8.06.4 5.1

4.0 3.9 2.9

121210

130175175

858585

505050

202020

999

332

1.21.41.3

0.91.11.1


25/443.22

Calculation of interim values: linear interpolation.

The connecting load group has to be stated in the order. On selection of a lower load group than stated inthe table. the E dim. of the clamp is reduced in accordance with the E dim. of the weld-on bracket (see page 3.8 ).

Lug dimensions: F less 1mm; B1 plus 2mm (see page 3.19 ).

Type 36 .. .1/2

Type 36 .. .4



36 11 1136 11 2136 11 2436 11 3136 11 34



36 13 1136 13 2136 13 2436 13 3136 13 34


OD 114.3 (ND 100 )

OD 133.0 (ND 125 )


36 14 1136 14 2136 14 2436 14 3136 14 34

permissible load (kN)OD 139.7 (ND 125 )


36 16 1136 16 2136 16 2436 16 3136 16 34



36 17 1136 17 1236 17 2136 17 2236 17 24

36 17 3136 17 3236 17 34


31

31

31

30

2951

2645

2333

172843

132534

121855

101746

7.71333

2030152030151530

270270315315340320320345

230245225240225225240240

50505050

1005050

100

3545304060304080

1111111113111116

56456446

7.611.58.3

10.918.7

7.710.526.0

27 241843

1434

1232

1027

7.819

2015301520

245300335310320

220215215215215

5050

10050

100

3530603060

1111131113

54645

6.77.5

17.97.2

15.4

28 231843

1434

1232

1027

7.919

2015301520

230285320295305

200200200200200

5050

10050

100

3530603060

1111131113

54645

6.06.7

16.26.4

14.3

28 231840

1437

1333

1127

8.018

2015201520

225275285285295

190190190190190

5050

10050

100

3530603060

1111131113

54545

5.86.3

12.86.1

13.0

28 241840

1535

1332

1026

8.016

2015201520

210270280280290

175175175175175

5050

10050

100

3535603060

1111131113

54545

5.16.5

11.75.5

11.8

3


26/443.23

Type 36 .. .1/2

Type 36 .. .4/5


The connecting load group has to be stated in the order. On selection of a lower load group than stated inthe table, the E dim. of the clamp is reduced in accordance with the E dim. of the weld-on bracket (see page 3.8 ).




36 19 11

36 19 1236 19 2136 19 2236 19 2436 19 3136 19 3236 19 34



36 22 1136 22 12

36 22 2136 22 2236 22 2436 22 3136 22 3236 22 34



36 24 1136 24 1236 24 21

36 24 2236 24 2436 24 2536 24 3136 24 3236 24 3436 24 35



36 26 1136 26 1236 26 2136 26 2236 26 2436 26 2536 26 3136 26 3236 26 3436 26 35


50

65

4965

4965

4965

4457

3848

294374

110

23355887

18325278

17274366

13193247

30302030305015203030

335335410410410425410410435435

345350340350340350340350340350

50505050

100100

5050

100100

45454045809040458090

11131113131611131616

6656674566

16.018.516.022.036.050.014.519.037.045.0

4557

3647

29

4374109

22

355886

18335279

17274466

13183244

303020

30305015203030

320320400

400400415395395420420

320330320

330320330320330320330

505050

50100100

5050

100100

454540

45809040458090

111311

13131611131616

665

6674566

15.017.015.0

21.535.048.013.518.035.043.0

4457

3849

284371

233558

183353

172844

132032

3030

203030152030

310310

385385385370370395

300300

290300290290300290

5050

5050

1005050

100

4545

404580404580

1113

111313111316

66

566456

14.016.0

14.020.033.012.516.534.0

46

57

37

49274368

233658

183454

172845

131933

30

30203030152030

285

285355355355350350375

270

275265275265265275265

50

505050

1005050

100

45

45404580404580

11

13111313111316

6

6566456

12.5

14.013.417.729.012.515.530.0


27/443.24

3




Type 36 .. .1/2/3

Type 36 .. .4/5



36 27 1136 27 1236 27 1436 27 1536 27 2136 27 2236 27 2436 27 2536 27 3136 27 3236 27 3436 27 35


C Emax Ad1 B B1 kgF max.Load gr.250 350 450 500 510 530 560100Type36 32 1136 32 1236 32 1336 32 1436 32 1536 32 2136 32 2236 32 2336 32 2436 32 2536 32 3136 32 32

36 32 3336 32 3436 32 35


OD 323.9 (ND 300 )


36 36 1136 36 1236 36 1336 36 1436 36 1536 36 2136 36 2236 36 2336 36 2436 36 2536 36 3136 36 3236 36 3336 36 3436 36 35


3765

100164200

3765

100166200

3557

100150182

325288

138166

274268

106143

21336184

13718305577

135

17254664

113

1218334783

203030505020303050501520303050

395395395410410480480480495495475495495495510

435445465445465435445465445465435445465445465

606060

120120

606060

120120

606060

120120

40456090

12040456090

12040456090

120

111313161611131316211113131621

566775667745667

202536547622304264912127415989

3557

100149182

344881

134163

284367

108143

22346385

1371830

5678

136

1725

4765

114

1218

314883

203030505020303050501520

303050

380380380395395450450450465465450470

470470485

405415430415430405415430415430405415

430415430

606060

120120

606060

120120

6060

60120120

40456090

12040456090

1204045

6090

120

111313161611131316211113

131621

566775667745

667

192434507120283858852025

395484

4457

100150

4865

110166

384781

120284373

109

22345886

18315076

17264264

12183145

303050502030305015203030

345345360360420420420435435435460460

350355345355345355345355345355345355

5050

100100

5050

100100

5050

100100

454580904045809040458090

111313161113131611131616

667756674566

171934421623375215204048


28/443.25




Type 36 .. .1/2/3

Type 36 .. .4/5

Type 37 .. .7



3765

100166279

3557

100151230

344890

139160

274269

106143

21336184

13718305577

135

17254665

113

12173447

83

2030305060203030505015203030

50

400400400415440485485485500500480500500500

515

450455475455475450455475455475450455475455

475

606060

120120

606060

120120

606060

120

120

40456090

12040456090

12040456090

120

1113131616111313162111131316

21

56678566774566

7

2126365587233142659321274260

91

Type36 37 1136 37 1236 37 1336 37 1436 37 1536 37 2136 37 2236 37 2336 37 2436 37 2536 37 3136 37 3236 37 3336 37 34

36 37 35



36 41 1136 41 1236 41 1336 41 1436 41 1536 41 2136 41 2236 41 2336 41 2436 41 2537 41 2736 41 3136 41 3236 41 3336 41 3436 41 3537 41 37


3765

100164277

3556

100149251

344483

137216

274273

105143252

21336183

137244

18295476

133240

16244664

112210

1218334682

136

2030305060203030505060152030305060

430430430445470510510510525525580510530530530545600

485495520495520485495520495520485485495520495520485

606060

120120

606060

120120310

606060

120120310

40456090

12040456090

120230

40456090

120230

1113131621111313162121111313162121

56678566778456678

232840619725344670

102183

2329456497

188


29/443.26

3




Type 36 .. .1/2/3

Type 36 .. .4/5

Type 37 .. .7/8



3765

100163276

3557

100148250

344584

136218

264176

103143257

21326082

137243

182954

75132240

162445

63111210

121833

4681136

2030305060203030505060152030

305060

440440440455480530530530545545595520540540

545560605

500510525510525500510525510525500500510525

510525500

606060

120120

606060

120120310

606060

120120310

40456090

12040456090

120230

404560

90120230

1113131621111313162121111313

162121

56678566778456

678

24304263

10026354873

106190

243147

66100190

Type36 42 1136 42 1236 42 1336 42 1436 42 1536 42 2136 42 2236 42 2336 42 2436 42 2537 42 2736 42 3136 42 3236 42 33

36 42 3436 42 3537 42 37



36 46 1136 46 1236 46 1336 46 1436 46 1536 46 2136 46 2236 46 2336 46 2436 46 2537 46 2736 46 3136 46 3236 46 3336 46 3436 46 3537 46 3737 46 38


3765

100161274

3557

100146248

325295

134228

264176

101143257

21326079

137243

16285374

131239347

16244562

110208309

1117324580

135207

203030506020303050506015203030506070

470470470485510550550550585585615550570570575590635675

540545565545565540545565545565535540545565545565535550

606060

120120

606060

120120310

606060

120120310330

40456090

12040456090

120230

40456090

120230250

131313162113131316212113131316212126

566785667784566789

26334770

11028385281

116200

26345271

112205290


30/443.27




Type 37 .. .1/2/3/4/5/6

Type 37 .. .7/8/9



75126180270356

57100137195269

4173

100153195

5181

116181211234380

4976

111172201222360

4576

108164198346

3771

94149183307

2747

68109132201

3050607070305050606060703030

50606070

515530560600600595620620650650650650625625

640665665710

595620630655590575590605625635670605580600

600640640605

170170230330310140170180240240250330140170

180230240330

130136180260230104130136180190190250104130

136180190250

1313162121131316212121261313

16212626

67899677888966

7889

4363

104183210

406590

148179198295

4263

91146180310

Type37 51 1137 51 1237 51 1337 51 1437 51 1737 51 2137 51 2237 51 2337 51 2437 51 2537 51 2637 51 2837 51 3137 51 32

37 51 3337 51 3437 51 3537 51 38




74126180270356

56100136195269

4172

100153195

5080

116181211233370

4876

110171201221350

4576

108163198346415

377194

149182304385

275168

108132196265

30506070703050506060607030305060607070

550565595635635640655655680680680725650650665695695735735

645670680705640630640655675685720655625650650690690655670

170170230330310140170180240240250330140170180230240330390

130136180260230104130136180190190250104130136180190250290

13131621211313162121212613131621212626

6789967788896678899

4566

110191226

436995

155187206330

446695

153188330405

Type37 56 1137 56 1237 56 1337 56 1437 56 1737 56 2137 56 2237 56 2337 56 2437 56 2537 56 2637 56 2837 56 3137 56 3237 56 3337 56 3437 56 3537 56 3837 56 39


31/44

3

3.28




Type 37 .. .1/2/3/4/5/6

Type 37 .. .7/8/9



75126182270359540

57100137197272412

4173

100155196300

5080

116180210233367

4876

110171200221347

45

76108162196344413

37

7193148182302380

26

5168107132195277

3050607070703050506060607030

305060607070

575590620660660660670685685715715715760685

685700730730770770

695720730755690705680690705725735770705680

700700740740705720

170170230330310330140170180240240250330140

170180230240330390

130136180260230250104130136180190190250104

130136180190250290

1616161621211616162121212616

161621212626

67899967788896

678899

4768

114197236295

4671

100164197218355

47

69100161198350430

Type37 61 1137 61 1237 61 1337 61 1437 61 1737 61 1837 61 2137 61 2237 61 2337 61 2437 61 2537 61 2637 61 2837 61 31

37 61 3237 61 3337 61 3437 61 3537 61 3837 61 39



75126182274360540

57100138198273413

4173

100155197300

5279

116180210233366

4976

110170200221347

4677

108164

198344413

387294

149

183302380

275368

108

133195277

3050607070703050506060607030305060

607070

605620650690690690700715715750750750790715715730755

755795795

750770780805740755730740755775785820755730750750790

790755770

170170230330310330145175180240240250330145175180230

240330390

130136180260230250110136136180190190250110136136180

190250290

1616161621211616162121212616161621

212626

67899967788896678

899

5073

120205250310

5581

104170207230375

5580

105168

206370455

Type37 66 1137 66 1237 66 1337 66 1437 66 1737 66 1837 66 2137 66 2237 66 2337 66 2437 66 2537 66 2637 66 2837 66 3137 66 3237 66 3337 66 34

37 66 3537 66 3837 66 39



32/443.29




Type 37 .. .1/2/3/4/5/6

Type 37 .. .8/9



75

126182

275

335

540

57

96138

200

244

414

41

68100

156

188

300

52

79

116

182

212

235

368

49

76

110

172

202

223

350

47

78

109

165

199

345

415

38

72

94

150

184

302

383

27

54

68

109

134

195

278

30

5060

70

70

70

30

50

50

60

60

60

70

30

30

50

60

60

70

70

635

650680

720

720

720

725

745

745

770

770

770

815

740

740

755

780

780

825

825

800

825835

860

880

810

780

795

810

830

840

875

810

780

805

805

845

845

810

825

170

170230

330

330

330

145

175

180

240

240

250

330

145

175

180

230

240

330

390

130

136180

260

260

250

110

136

136

180

190

190

250

110

136

136

180

190

250

290

16

1616

16

21

21

16

16

16

21

21

21

26

16

16

16

21

21

26

26

6

78

9

9

9

6

7

7

8

8

8

9

6

6

7

8

8

9

9

53

75124

211

240

325

58

85

110

177

215

240

390

59

84

109

173

215

385

475

Type37 71 11

37 71 1237 71 13

37 71 14

37 71 15

37 71 18

37 71 21

37 71 22

37 71 23

37 71 24

37 71 25

37 71 26

37 71 28

37 71 31

37 71 32

37 71 33

37 71 34

37 71 35

37 71 38

37 71 39



75

125

182

280

335

400

540

56

100

138

216

244

300

414

41

70

100

156

188

236

300

51

79

116

182

236

370

49

76

110

173

223

350

47

78

109

166

200347

417

38

73

95

151

185305

385

28

53

69

110

135197

280

30

50

60

70

70

70

70

30

50

50

60

60

70

30

30

50

60

6070

70

665

680

710

750

750

750

750

760

775

775

800

800

845

765

765

780

805

805850

850

850

875

885

910

930

935

860

830

845

860

880

925

860

830

855

855

895

895860

875

170

170

230

330

330

330

330

145

175

180

240

250

330

145

175

180

230

240330

390

130

136

180

260

260

260

250

110

136

136

180

190

250

110

136

136

180

190250

290

16

16

16

16

21

21

21

16

16

16

21

21

26

16

16

16

21

2126

26

6

7

8

9

9

9

9

6

7

7

8

8

9

6

6

7

8

89

9

56

80

128

222

247

270

345

62

90

113

185

245

410

62

87

113

180

222405

500

Type37 76 11

37 76 12

37 76 13

37 76 14

37 76 15

37 76 16

37 76 18

37 76 21

37 76 22

37 76 23

37 76 24

37 76 26

37 76 28

37 76 31

37 76 32

37 76 33

37 76 34

37 76 3537 76 38

37 76 39



33/443.30

3




Type 37 .. .1/2/3/4/5/6

Type 37 .. .8/9



74125181280335400540

56100137215244300413

4071

100156188235300

5179

116182236370

4976

110173224350

47

78110166201350420

38

7395153186306387

28

5469107135198280

3050607070707030505060607030

305060607070

700715745785785785785790805805830830875790

790805830830875875

905925935960980985910880895910930975910880

905910945945910925

170170230330330330330145175180240250330145

175180230240330390

130136180260260260250110136136180190250110

136136180190250290

1616161621212116161621212616

161621212626

67899996778896

678899

5984

134230255280360

6595

118190255430

65

92117185230420520

Type37 81 1137 81 1237 81 1337 81 1437 81 1537 81 1637 81 1837 81 2137 81 2237 81 2337 81 2437 81 2637 81 2837 81 31

37 81 3237 81 3337 81 3437 81 3537 81 3837 81 39



74120181280335400540

5694

137216244300413

4067

100156188236300

5280

117184238374450

4977

111174226354425

4778

109

168203350420

387396

149188307388

285466

97137200283

3050607070707030505060607070303050

60607070

760775805845845845845840855855880880925925850850865

880880935935

1005103010401060108010901010

985995

10101030108010101020

98510051010

1045104510101025

170170230330330330330145175180240250330390145175180

230240330390

130136180260260260250110136136180190250290110136136

180190250290

1616161621212116161621212626161616

21212626

67899996778899667

8899

6693

144240270295390

72103125200270460555

73101126

195240455570


Type37 91 1137 91 1237 91 1337 91 1437 91 1537 91 1637 91 1837 91 2137 91 2237 91 2337 91 2437 91 2637 91 2837 91 2937 91 3137 91 3237 91 33

37 91 3437 91 3537 91 3837 91 39


34/443.31

LISEGA dynamic pipe clamps are suppliedready for installation complete with all thenuts and bolts required.It is recommended that units be stored onlyin closed rooms. If storage in the open isunavoidable, they must be protected fromdirt and moisture.

Prevention of twisting To prevent the clamp from twisting, it isrecommended that a shear lug be weldedto the pipe (see also page 3.19).The lug dimensions can be found in theselection tables for dynamic clamps onpages 3.21 3.30.

Type 36This design has a solid upper yoke with inte-grated connection bracket and, depending onthe load range, one or two U-bolts with inlayplate are provided.

For installation, remove the preassembledU-bolts. Then place the yoke over the shear lug. Reassemble the U-bolt and inlay from

the opposite side, tightening the nuts onlylightly at first. Then check and position theclamp as required. Finally, the nuts can beproperly tightened and countered.

DYNAMIC PIPE CLAMPSINSTALLATION INSTRUCTIONS

Type 37This is the heavier type for larger pipe dia-meters and higher loads. Normally, thebracket type 35 is welded to the upper yoke.If the bracket is supplied loose on customer request, it must be welded on site followingthe welding instructions on page 3.16. Thecounterpart to the yoke consists of one or two flat steel straps depending on load. Thestraps are pinned to the yoke to make trans-port easier. For installation, the straps mustbe removed from the forked blocks by loo-sening the pin connection. The yoke isplaced on the shear lug. From the oppositeside the flat steel strap is fitted into the bolt-on clevises, fixed with the pins and securedby cotter pins. The clamp is then checked andpositioned as required.

Finally the nuts are properly tightened. Thehex nuts must be locked in position by ben-ding the tab washers to prevent uninten-tional loosing.

Type 36 .. .1/2/3

Type 37 .. .1/2/3/4/5/6

Type 36 .. .4/5

Type 37 .. .7/8/9


35/443.32

3


36/44

Short lived but high magnitude fluid transientloads can be compensated by smaller, definedsupport loads. As a result, if energy absor-bers are installed, any reinforcement of exis-ting structures can be dispensed with.In new constructions, the load limitationpermits a more economical use of steel rightfrom the start.

Replacement for box frame constructionsEnergy absorbers are ideally suited to theguidance and limitation of thermal move-ments. This way, not only are the usual andoften expensive box frame constructions notrequired, but frictional forces between the

piping and the frame are also avoided.

Pipe whip restraint An ideal application for energy absorbers isas protection from pipe whip. When used inangular arrangements, large forces can beabsorbed. The direction of defined lines of force can be determined by the arrangement.The advantage over U-bolt designs consistsin the far less restricted effective radius.

ENERGY ABSORBERTYPE 32

A fully deve-loped concept is

needed for the best pos-sible protection of plant components

against pressure shocks. In the specific useof the most appropriate components, safety and economic efficiency need not excludeeach other.

Field of applicationThe field of application for LISEGA energyabsorbers lies roughly between the LISEGArigid struts and shock absorbers. Energy ab-

sorbers are used just like these components,to suppress abrupt displacements in pipingor other components. In contrast to rigidstruts and shock absorbers, energy absorbersare equipped with an adjustable free stroke(0 30mm) allowing slight thermal move-ments without any resistance.

Conversion into deformation energy After passing through the free stroke, possiblepressure shocks are absorbed by limitingstops, and up to a defined load maximum(nominal load) are transferred to the surroun-ding structure. Forces in excess of this or peaks of force are converted into deformationenergy by the energy absorbers, rather thanloading the other attached components.Piping displacements within the adjusted rangeof the free stroke are acceptable, providedthat the permissible stresses are not therebyexceeded. If necessary, corresponding proof must be supplied. Special software andadvice can be offered if required.

Maintenance-free useLISEGA energy absorbers are ideal for dealingwith small or negligible thermal movementswhen connected components are to be pro-tected from dynamic overload in a controlledmanner. The energy absorbers contain nowear parts of any kind, and therefore re-quire no maintenance.

Protection from water hammer Energy absorbers are ideal for protectingother connected components against pos-sible water hammer.

3.33

Energy absorber used instead of a dual guide.The box frame can be dispensed with.


37/44

Analysis of piping behavior Where energy absorbers are used, the GAPPprogram can be applied to perform seismicand fluid transient analysis. GAPP allowspiping to displace within the permissible tole-rance for the movements. For the load event,the specific load limiting property of energyabsorbers is taken into account.In response spectrum analyses, the programreproduces an equivalent linear spring charac-teristic to approximate to the non-linear situa-tion. When fluid transient analyses are per-formed, the program uses time historymethods.

The unique capacity of the energy absor-ber to take up and convert kinetic energy brings the user valuable benefits:

limitation of dynamic loads for attachedcomponents

lighter steel constructions enabled

no need to strengthen auxiliarystructures

small installation dimensions minimizedanger of interference

thermal piping movement not impeded

no maintenance required due toabsence of wear parts

no recurrent testing required

simple installation via lengthadjustment

Replacement of shock absorbersWhere thermal movements are relatively small,energy absorbers constitute an ideal replace-ment for earlier types of shock absorbers,often prone to failure. In this way, costlyrepairs and recurrent tests are avoided.

Development cooperationThe development of type 32 energy absor-bers is the result of specific and successfulcooperation between SARGENT & LUNDY,aleading American engineering company, and

LISEGA .

SARGENT & LUNDY also created the calcula-tion software, or GAPP program. Both thisprog-ram and the energy absorbers themsel-ves have been rigorously tested by theAmericanNRC (Nuclear Reactor Commission),and approved for use in nuclear power stati-ons.

3.34

3flange

special lug

shortextension

extension kittype 33

To enable energy absorbers to be fitted to existingconnections, an assortment of special adaptors isavailable besides the standard extension (type 33)


38/443.35

ENERGY ABSORBERS TYPE 32INSTALLATION DIMENSIONS

Individual useThe standard designs shown in the table donot show the full scope of supply possibilities.LISEGA can adapt the products to the specialrequirements of the user.

When the nominal load is ex-ceeded, the increased force and movement is converted into de-

formation energy.

Maximum deformation travelin the direction of tension and compression.

Dimensions at the midpoint of free strokes t1/t2, and a lengthadjustment of A dimension.When changing t2, E dimension

is either reduced or increased.

Order details:Energy absorbertype 32 .. 16t1= t2= mmwith two weld-on bracketstype 35 .. ..

Marking:

This especially relates to applications whereload and stroke exceed standard parameters.

total length adjustment min. thread engagement

indicator for absorbed energyfree stroke adjustment

free stroke (tension)free stroke (compression)

on demand

Type

32 18 1632 38 1632 42 1632 52 1632 62 1632 72 1632 82 1632 92 16

Nom.load(kN) t1 t2 D d3

38

1846

100200350550

5.05.05.05.06.59.5

12.5

566080

115130195250

10121520305060

300355440490575715945

18505865

100130165

152022.530456075

9101216223544

85 5095 50

125 75150 75165 75175 75225 75

0-200-220-250-250-250-280-30

0-200-220-250-250-250-280-30

E A F R SG Weight(kg)0.81.83.6

11.518.547.0

105.0

s


39/44

is required, using the adjustment device (H).Corresponding procedures are repeatable upto a maximum deformation travel (s).

InstallationThe energy absorbers correspond to theload groups in Product Group 3 (dynamiccomponents) and are correspondingly loadand connection compatible with other connection components of this productgroup. Attention is drawn to the notices onpages 3.3 and 3.15 to 3.16.

Functional qualificationThe LISEGA energy absorbers have undergonea stringent test program to prove their func-tional reliability. Adequate safety marginshave been proven by numerous dynamicand static loading tests.

3.36

3

MODE OF OPERATIONAn energy absorber works via an adjustablefree stroke that absorbs thermal movements.The adjustment of this free stroke can bemade in the range of 25 mm (for a mediumsized design). Within this range the pipe isfree to move without resistance. Dynamicshocks, on the other hand, are limited intheir movement by stops. The resulting forcesare transferred to the surrounding structuresup to the given nominal load, and whenabove that, are transformed into deforma-tion energy by the energy absorber. Thishas the effect of providing a controlled pro-tection from overload for the attached com-ponents.

The unit consists of an austenitic outer sleeve(A) with a defined undersize, into whichtapered bronze disks (B) have been forcefitted. The outer sleeve is closed off with abase plate (C), onto which the connectionlug (D) is attached. Forces are transferredthroughout the whole unit by the stops (E)and the shaft (F).

In the event of a dynamic force exceedingthe insertion force of the tapered disks(nominal load), the disk affected is drivenforward and leads to an expansion of thesleeve. This way, the excess forces are keptclear of the attachment structures via con-version into deformation energy. If such aprocess has occurred, the advance of thetapered disk affected can be read off on theindicator rod (G). For further use of the ener-gy absorber, only a corresponding readjust-ment of the free stroke for the new position

ENERGY ABSORBERMODE OF OPERATION

wedge B

free stroke (tension)free stroke (compression)

total length adjustment

free stroke adjustment H indicator for absorbed energy

Documents

3 - Shock Absorbers, Energy Absorbers, Rigid Struts