FlangedJoints

5/21/2018 FlangedJoints

1/444.16-1

4.16 Design Rules For Flanged Joints (Revision 6)

4.16.0 Table of Contents............................................................................................................ 14.16.1 Scope ...............................................................................................................................14.16.2 Design Considerations...................................................................................................14.16.3 Flange Types ...................................................................................................................34.16.4 Flange Materials..............................................................................................................34.16.5 Gasket Materials .............................................................................................................44.16.6 Design Bolt Loads ..........................................................................................................54.16.7 Flange Design Procedure............................................................................................... 94.16.8 Split Loose Type Flanges............................................................................................. 104.16.9 Noncircular Shaped Flanges With A Circular Bore...................................................114.16.10Flanges With Nut Stops................................................................................................ 114.16.11Qualification Of Assembly Procedures And Assemblers.........................................114.16.12Nomenclature................................................................................................................124.16.13Tables............................................................................................................................. 164.16.14Figures ...........................................................................................................................36

4.16.1 Scope

4.16.1.1 The rules in this paragraph can be used to design circular flanges subject to internal and/orexternal pressure. These rules provide for hydrostatic end loads, gasket seating, and externally applied axialforce and net-section bending moment.

4.16.1.2 The rules in this paragraph apply to the design of bolted flange connections with gaskets that areentirely located within the circle enclosed by the bolt holes. The rules do not cover the case where thegasket extends beyond the bolt hole circle.

4.16.1.3 It is recommended that bolted flange connections conforming to the standards listed inparagraph 4.1.11 be used for connections to external piping. These standards may be used for other boltedflange connections within the limits of size in the standard and pressure-temperature ratings permitted in

paragraph 4.1.11. The ratings in these standards are based on the hub dimensions given or on theminimum specified thickness of flanged fittings of integral construction. Flanges fabricated from rings may beused in place of the hub flanges in these standards provided that their strength, calculated by the rules in thisparagraph, is not less than that calculated for the corresponding size of hub flange.

4.16.1.4 The rules of this paragraph should not be construed to prohibit the use of other types of flangedconnections provided they are designed in accordance with good engineering practice and method of designis acceptable to the user and Inspector.

4.16.2 Design Considerations

4.16.2.1 The design of a flange involves the selection of the flange type, gasket material, flange facing,bolting, hub proportions, flange width, and flange thickness, and depending on the method used to compute

the bolt load, a tightness class. The flange dimensions shall be designed such that the stresses in the flangeand the flange rigidity satisfy the acceptability criteria of this paragraph. Annex 4.B is included that providesa discussion of the design considerations for bolted flanged connections.

4.16.2.2 In the design of a bolted flange connection, calculations shall be made for the following twodesign conditions, and the most severe condition shall govern the design of the flanged joint.

a) Operating Conditions The conditions required to resist the hydrostatic end force of the designpressure and any applied external forces and moments tending to part the joint at the designtemperature.


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4.16-2 ASME Section VIII, Division 2 ReWrite Revision 6_______________________________________________________________________________________________

b) Gasket Seating Condition The conditions existing when the gasket or joint-contact surface is seatedby applying an initial load with the bolts during assembly the joint, at atmospheric temperature andpressure.

4.16.2.3 Calculations shall be performed using dimensions of the flange in the corroded condition and theuncorroded condition, and the more severe case shall control.

4.16.2.4 In the design of flange pairs that are separated by a pressure retaining plate such as atubesheet, each flange is designed for its particular design loads of pressure, gasket reactions, anddepending on the method used to compute the bolt load, a tightness class. The bolt load used to designeach flange, however, is that load common to the flange pair and equal to the larger of the bolt loadscalculated for each flange individually. No additional rules are required for design of flange pairs. After theloads for the most severe condition are determined, calculations shall be made for each flange following therules of this paragraph.

4.16.2.5 In the design of flange pairs where pass partitions with gaskets are used, the gasket loads fromthe partition(s) shall be included in the calculation of bolt loads. Partition gaskets may have different gasketconstants than the ring gasket inside the bolt circle. In the design of flanges with noncircular gaskets or withpartitions of any shape, gasket reactions from all surfaces with gaskets shall be included in calculating boltloads.

4.16.2.6 Two methods are provided for determining the design bolt load for a flanged joint. The methodto be used in the design is subject to agreement between the designer and purchaser.

a) Method A The bolt load is established based on two gasket parameters, a flange leakage criterion isnot explicitly included in the design procedure.

b) Method B The bolt load is established based on four gasket parameters, a flange leakage criterion isexplicitly included in the design procedure. The in-service gasket condition may require adjustment tothe bolt load to maintain the desired gasket tightness.

1) Tightness is expressed through a tightness parameter, pT . The tightness parameter, pT , is a

measure of tightness that has been defined as proportional to pressure and inversely proportionalto the square root of leak rate, or

*

*p

P LT

P L

! "#$ %

& ' (4.16.1)

2) Numerically,p

T is the dimensionless quantity that is the product of the ratio of pressure divided by

atmospheric pressure and the square root of the ratio of a reference mass leak rate per unitdiameter divided by a measured mass leak rate per unit diameter, all in consistent units. In this

paragraph, the reference leak rate,*L , is 1 mg He/sec/150 mm diameter at one atmosphere. For

example, for a 10 in. joint leaking 0.05 mg He/sec at 4 atmospheres,

4 1 15023.3

1 0.5 254

pT ! "# #$ %

& '

(4.16.2)

3) The flanged joint shall be designed to satisfy a tightness requirement that is established by theselection of a Tightness Class appropriate for the service conditions. The minimum required

tightnessminp

T is associated with a maximum permitted leak rate for the selected class.

4) The Tightness Class and associated value of cT are related to leak rate as shown in Table 4.16.1.

The parameter cT shall be selected for the desired tightness class from Table 4.16.1 that provides


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Revision 6 ASME Section VIII, Division 2 ReWrite 4.16-3_______________________________________________________________________________________________

some representative tightness classes. Unless otherwise specified, the value for cT for Class I

shall be selected from Table 4.16.1, or calculated for other classes by the following equation:

0.5

0.002: / /cT Leak rate in mg He sec mm diameter

Helium Leak Rate

! "#$ %

& ' (4.16.3)

0.50.0004

: / /cT Leak rate in lb He sec in diameter Helium Leak Rate

! "#$ %

& ' (4.16.4)

4.16.3 Flange Types

4.16.3.1 For the purpose of computation, there are two major categories of flanges:

a) Integral Type Flanges This type covers designs where the flange is cast or forged integrally with thenozzle neck, vessel or pipe wall, butt welded thereto, or attached by other forms of welding such thatthe flange and nozzle neck, vessel or pipe wall are structurally equivalent to integral construction.Integral flanges shall be designed considering structural interaction between the flange and the nozzleneck, vessel, or pipe wall, which the rules account for by considering the neck or wall to act as a hub.

Integral type flanges are referenced below. The design bolt loads are shown in Figures 4.16.1 and4.16.2.

1) Integral type flanges Figure 4.16.1 Sketch (a) and Table 4.2.9, Detail 19

2) Integral type flanges where1 og g# Figure 4.16.1 Sketch (b)

3) Integral type flanges with a hub Figure 4.16.2 and Table 4.2.9, Details 6,7,and 8

4) Integral type flanges with nut stops Figure 4.16.3 and Figure 4.16.4

b) Loose Type Flanges This type covers those designs in which the flange has no substantial integralconnection to the nozzle neck, vessel, or pipe wall, and includes welded flange connections where thewelds are not considered to give the mechanical strength equivalent of an integral attachment. Integraltype flanges are referenced below. The design bolt loads are shown in Figures 4.16.5, 4.16.6, and

4.16.7.

1) Loose type flanges Figure 4.16.5 and Table 4.2.9, Details 1,2,3 and 4

2) Loose type lap joint flanges Figure 4.16.6 and Table 4.2.7, Detail 5

3) Loose type threaded flanges Figure 4.16.7

4.16.3.2 The integral and loose type flanges described above can also be applied to reverse flangeconfigurations. Integral and loose type reverse flanges are shown in Figure 4.16.8.

4.16.4 Flange Materials

4.16.4.1 Materials used in the construction of bolted flange connections shall comply with the

requirements given in Part 3 .

4.16.4.2 Flanges made from ferritic steel shall be given a normalizing or full-annealing heat treatmentwhen the thickness of the flange section exceeds 75 mm (3 in.).

4.16.4.3 Material on which welding is to be performed shall be proved to be of weldable quality.Satisfactory qualification of the welding procedure under Section IX is considered as proof. Welding shall notbe performed on steel that has a carbon content greater than 0.35%. All welding on flange connections shallcomply with the requirements for postweld heat treatment given in Part 6 .

4.16.4.4 Fabricated flanges with hub shall be in accordance with the following:


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a) Flanges with hubs may be machined from a hot rolled or forged billet or forged bar. The axis of thefinished flange shall be parallel to the long axis of the original billet or bar, but these axes need not beconcentric.

b) Flanges with hubs, except as permitted in 4.16.4.4.a, shall not be machined from plate or bar stockmaterial unless the material has been formed into a ring, and further provided that:

1) In a ring formed from plate, the original plate surfaces are parallel to the axis of the finished flange;

2) The joints in the ring are welded butt joints that conform to the requirements of Part 6. Thethickness to be used to determine postweld heat treatment and radiographic requirements shall be

( )min , 2t A B* +,- . .

c) The back of the flange and the outer surface of the hub are examined by either the magnetic particlemethod or the liquid penetrant method in accordance with Part 7.

4.16.4.5 Bolts, studs, nuts, and washers shall comply with the requirements of Part 3 and referencedstandards. It is recommended that bolts and studs have a nominal diameter of not less than 12 mm (0.5 in.).If bolts or stubs smaller than 12 mm (0.5 in.) are used, then ferrous bolting material shall be of alloy steel.Precautions shall be taken to avoid overstressing small-diameter bolts. When washers are used, they shallbe through hardened to minimize the potential for galling.

COMMENT: Paragraph 4.16.4 should be moved to Section 3.

4.16.5 Gasket Materials

4.16.5.1 Gasket materials shall be selected that are suitable for the design conditions over the intendedlength of service. Corrosion, chemical attack, creep and thermal degradation of gasket materials over timeshall be considered.

4.16.5.2 The gasket constants for the design of the bolt load using Method A, m and y , are provided in

Table 4.16.2. Other values for the gasket constants may be used if based on actual testing or data in the

literature.

4.16.5.3 The gasket constants for the design of the bolt load using Method B, sG , a , bG and maxPT are

provided in Table 4.16.3. Other values for the gasket constants may be used if based on actual testing ordata in the literature. These gaskets shall meet the following requirements.

a) Gasket constants sG , a , bG and maxPT shall be certified by test.

1) The gasket constants taken from Table 4.16.3 may be considered as certified.

2) Gasket constants that are different from those given in Table 4.16.3 may be used provided theManufacturer's Data Report cites the source test document that certifies the constants for thespecified gasket material and type.

3) If a test is performed, the test shall be in accordance with the PVRC ROTT procedures as given inAppendices A and B, Welding Research Council Bulletin 427, Leakage and EmissionCharacteristics of Sheet Gaskets: Report No.1: Fugitive Emission Characteristics of Gaskets andReport No.2: Exploratory Investigation of the Leakage Stabilization Time at Room Temperature forFlexible Graphite and PTFE Based Sheet Gaskets.

b) Temperature limitations on gasket constants.

1) Gasket constants bG and a are for the assembly condition that is assumed to take place at

ambient temperature, and for a new gasket. However, changes in constants bG and a at elevated


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temperatures are not needed since they are not used in the design process and do not affect theflange design.

2) Gasket constant sG reflects the operating condition. The constant sG of Table 4.16.3 is valid for

various materials and gasket temperatures not exceeding the following:

i) 121C (250F) for elastomer or reinforced elastomer sheet materials.

ii) 315C (600F) for flexible graphite sheet materials.

iii) 482C (900F) for flexible graphite-steel or high alloy composite gaskets where thegraphite is encapsulated by the metal component after seating. This includes spiralwound, metal jacketed, profiled metal and corrugated metal components.

iv) As limited by paragraph 4.16.5.1 for solid metal gaskets.

3) The temperature limit for gasket constant, sG , other than those listed in paragraph 4.16.5.3.b.2 ,

shall be established by an acceptable test that accounts for thermal degradation over the life of thegasket, and included as part of the certification of gasket constants.

c) The width of sheet and composite gaskets, N , shall be considered as follows:

1) A width no less than that given in Table 4.16.4 is recommended.

2) A width no less than that given in Table 4.16.4 shall be used for purposes of computing gA .

4.16.6 Design Bolt Loads

4.16.6.1 The flange bolt load to be used in the design shall be calculated using one of the following twomethods.

4.16.6.2 Method A A procedure to determine the bolt loads for the operating and gasket seatingconditions is shown below.

a) STEP 1 Determine the design pressure and temperature of the flange joint.

b) STEP 2 Select a gasket and determine the gasket factors m and y from Table 4.16.2, or other

sources.

c) STEP 3 Determine the width of the gasket, N , basic gasket seating width, 0b , the effective gasket

seating width, b , and the location of the gasket reaction, G , based on the flange and gasket geometry,the information in Table 4.16.5 and Figure 4.16.9, and the equations shown below.

0 0 6 (0.25 .)b b when b mm in# / (4.16.5)

000.5 6 (0.25 .)ul

ul

bb C when b mm in

C# 0 (4.16.6)

d) STEP 4 Determine the design bolt load for the operating condition.

20.785 2oW G P b GmP for non self energized gaskets1# 2 , , (4.16.7)

20.785oW G P for self energized gaskets# , (4.16.8)

e) STEP 5 Determine the design bolt load for the gasket seating condition.

2

m bg bg

A AW S

2! "#$ %

& ' (4.16.9)


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The parameter bA is the actual total cross sectional area of the bolts that is selected such that b mA A3 ,where

max , gso

m

bo bg

WWA

S S

* +# 4 5

4 5- . (4.16.10)

( )gs usW bG C y for non self energized gaskets1# , , (4.16.11)

0.0gsW for self energized gaskets# , (4.16.12)

4.16.6.3 Method B A procedure to determine the bolt loads for the operating and gasket seatingconditions using an alternative procedure that includes a flange leakage criterion is shown below.

a) STEP 1 Determine the design pressure and temperature of the flange joint.

b) STEP 2 Select a gasket and determine the gasket factors sG , a , bG , lS , cS , and maxPT from Table

4.16.3.

c) STEP 3 Determine the width of the gasket, N , basic gasket seating width, 0b , the effective gasketseating width, b , and the location of the gasket reaction, G , and the gasket contact area, gA (see

paragraph 4.16.5.3.c.2), based on the flange and gasket geometry, the information in Table 4.16.6 andFigure 4.16.9, and the equations shown below.

0 0 12 (0.5 .)b b when b mm in# / (4.16.13)

00 12 (0.5 .)

2ul

ul

bb C when b mm in

C# 0 (4.16.14)

d) STEP 4 Select an assembly, 6, from Table 4.16.7.

e) STEP 5 Determine the tightness class,cT , and the minimum required tightness, minPT .

min 0.1243P cT T P# (4.16.15)

f) STEP 6 Determine the assembly tightness, PaT . The assembly tightness must satisfy the equation

shown below. Any value of PaT that satisfies this equation can be used to determine the design bolt

load.

min max1.5 P Pa PT T T/ / (4.16.16)

The following iterative procedure can be used to obtain an optimum value for the assembly tightness

and bolt load.

1) STEP 6.1 Set the upper and lower bounds for PaT

max

U

Pa PT T# (4.16.17)

min1.5L

Pa PT T# (4.16.18)

2) STEP 6.2 determine the average value of PaT .


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( )0.5VG U LPa Pa PaT T T# 2 (4.16.19)

3) STEP 6.3 Compute the design gasket stress,yaS .

( )a

AVGbya us Pa

GS C T

6

! "# $ %

& ' (4.16.20)

4) STEP 6.4 Compute the minimum gasket operating stress to meet the required joint tightness,

1mS .

( )1 mink

m us s P S C G T # (4.16.21)

where

log

log

ya

s

AVG

Pa

S

Gk

T

6* +4 5- .#* +- .

(4.16.22)

5) STEP 6.5 Compute the average operating gasket stress after the design pressure and external

loads are applied, 2mS .

( )( )

2

2

0.785 4

1.5

Ayabo Em us

bg gg p

G P FSS QMS C

S GAA A

6* +2! "! "4 5# , ,$ %$ %$ % 24 5& '& '- .

(4.16.23)

6) STEP 6.6 Compute the difference between 2mS and 1mS , 2 1D

m m mS S S# , .

i) If 0.0DmS 0 , then setU AVG

Pa PaT T# and go to STEP 6.2.

ii) If 0.0D

mS 7 , then setL AVG

Pa PaT T# and go to STEP 6.2.

iii) If 0.0DmS # , or the absolute value in the difference between the bounds of the iteration,

( )abs U LPa PaT T, , is small, then set AVGPa PaT T# . This is the optimum value of theassembly tightness; go to Step 6 to determine the minimum required operating boltload.

g) STEP 7 Determine the minimum required operating bolt load.

( )2 4

0.785 Emo mo g p AW G P S A A F G

# 2 2 2 2 (4.16.24)

where

( )1 3

2max , , ,

us l

mo m m

C SPS S S

6 6

* +# 4 5

- . (4.16.25)

The parameters1m

S and3m

S are computed using Equations (4.16.21) and (4.16.23) with the value of

minPT determined in STEP 5.

h) STEP 8 Determine the required and actual bolt areas.


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mom

bo

WA

S# (4.16.26)

The actual bolt area is determined by selecting a number and size of bolts so that the actual total area,

bA , is greater than or equal to the minimum required area, mA .

i) STEP 9 Determine if the actual bolt area satisfies the following criterion.

( ) ( )1.5 2 b bg c g pA S S A A6, / 2 (4.16.27)

j) STEP 10 Determine the design bolt load for the operating condition.

o b boW A S# (4.16.28)

k) STEP 11 Determine the design bolt load for the gasket seating condition.

g b bgW A S# (4.16.29)

l) STEP 12 Determine the minimum assembly bolt load for the test pressure,t

P.

8 91 2 3max , ,am a a aW W W W # (4.16.30)

where

( ) 211

0.785a mo g p t

W S A A G P 6

! "* +# 2 2$ % - .

& ' (4.16.31)

( )221

0.785 1a t ya g pW G P S A A6

! "# , 2 2$ %

& ' (4.16.32)

3 1.5a b bg W A S# (4.16.33)

m) STEP 13 Determine the minimum operating bolt load.

( ) 214

0.785 Eom m f g p AW S A A G P F G

# 2 2 2 2 (4.16.34)

where

( )1 minfk

m f s P S G T# (4.16.35)

log

log

yaf

s

f

Paf

S

GkT

* +4 5- .#* +- .

(4.16.36)

1

max

ayaf

paf P

b

ST T

G

! "$ %& '! "

# /$ %& '

(4.16.37)


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( )am

yaf yam

g p

WS S

A A# /

2 (4.16.38)

( )maxa

yam b PS G T# (4.16.39)

COMMENT: In this write-up, the theory behind the bolt-loadcalculation is not explained. Only those calculations requiredto determine the design bolt load are described. Also, what dowe tell the designer to do with the bolt loads computed inSteps 12 and 13?

4.16.7 Flange Design Procedure

4.16.7.1 The procedure in this paragraph can be used to design circular integral, loose or reverseflanges, subject to internal or external pressure, and external loadings. The procedure can be used witheither of the methods for determining bolt loads and incorporates both a strength check and rigidity check forflange rotation.

4.16.7.2 A procedure to design a flange is shown below.

a) This STEP 1 Determine the design pressure and temperature of the flange joint, and the external net-

section axial force, F , and bending moment, E . If the pressure is negative, the absolute value of

the pressure should be used in this procedure.

b) STEP 2 Determine the design bolt loads for operating condition, oW , and the gasket seating

condition, gW , and corresponding actual bolt area, bA , using Method A or Method B in paragraph

4.16.6.

c) STEP 3 Determine an initial flange geometry, in addition to the information required to determine thebolt load, the following geometric parameters are required:

1) The flange bore, B

2) The bolt circle diameter, C

3) The outside diameter of the flange, A

4) The flange thickness, t

5) The thickness of the hub at the large end, 1g

6) The thickness of the hub at the small end, 0g

7) The hub length, h

d) STEP 4 Determine the flange forces.

20.785DH B P# (4.16.40)

20.785H G P# (4.16.41)


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T DH H H# , (4.16.42)

G oH W H# , (4.16.43)

e) STEP 5 Determine the flange moment for the operating condition using Equation (4.16.44) or

Equation (4.16.45), as applicable. In these equations, Dh , Th , and Gh are determined from Table

4.16.8, the moment oe is calculated using Equation (4.16.46), and I and pI are determined fromTable 4.16.9.

( )abso D D T T G G oe sH h H h H h M F Internal pressure* +# 2 2 2- . (4.16.44)

( ) ( )( )abso D D G T T G oe sH h h H h h M F External pressure* +# , 2 , 2- . (4.16.45)

( )

( ) ( ) ( )

2 14

2 1 2

GDoe E A D G

p D

I hhM F h h

I I C h G

:

:

* + * +2# , 2 24 5 4 5

2 2 ,4 54 5 - .- . (4.16.46)

f) STEP 6 Determine the flange moment for the gasket seating condition using Equation (4.16.47) orEquation (4.16.48), as applicable.

( )2

g s

g

W C G F Internal pressure

,# (4.16.47)

g g G sW h F External pressure# (4.16.48)

g) STEP 7 Determine the flange stress factors using the equations in Tables 4.16.10 and 4.16.11.

h) STEP 8 Determine the flange stresses for the operating and gasket seating conditions using theequations in Table 4.16.12.

i) STEP 9 Check the flange stress acceptance criteria. The two criteria shown below need to beevaluated. If the stress criteria are satisfied, then go to STEP 10. If the stress criteria are not satisfied,then re-proportion the flange dimensions and go to STEP 4.

1) Allowable Normal Stress The criteria to evaluate the normal stresses for the operating andgasket seating conditions are shown in Table 4.16.13.

2) Allowable Shear Stresses In the case of loose type flanges with laps, as shown in Fig. 4.16.6where the gasket is so located that the lap is subjected to shear, the shearing stress shall not

exceed 0.8 noS or 0.8 ngS , as applicable, for the material of the lap. In the case of welded flanges

where the nozzle neck, vessel, or pipe wall extends near to the flange face and may form the

gasket contact face, the shearing stress carried by the welds shall not exceed 0.8 noS or 0.8 ngS ,

as applicable. The shearing stress shall be calculated for both the operating and gasket seatingload cases. Similar situations where flange parts are subjected to shearing stresses shall bechecked to the same requirement.

j) STEP 10 Check the flange rigidity criteria in Table 4.16.14. If the flange rigidity criterion is satisfied,then the design is complete. If the flange rigidity criterion is not satisfied, then re-proportion the flangedimensions and go to STEP 4.

4.16.8 Split Loose Type Flanges

Loose flanges split across a diameter and designed under the rules given in this paragraph may be usedunder the following provisions.


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a) When the flange consists of a single split flange or flange ring, it shall be designed as if it were a solid

flange (without splits), using 200% of the total moment, 2.0sF # .

b) When the flange consists of two split rings, each ring shall be designed as if it were a solid flange

(without splits), using 75% of the total moment, 0.75sF # . The pair of rings shall be assembled so that

the splits in one ring are 90 degrees from the splits in the other ring.

c) The flange split locations should preferably be midway between bolt holes.

4.16.9 Noncircular Shaped Flanges With A Circular Bore

The outside diameter, A , for a noncircular flange with a circular bore shall be taken as the diameter of thelargest circle, concentric with the bore, inscribed entirely within the outside edges of the flange. The boltloads, flange moments, and stresses shall be calculated in the same manner as that for a circular flangeusing a bolt circle whose size is established by drawing a circle through the centers of the outermost bolts.

4.16.10 Flanges With Nut Stops

When flanges are designed per this paragraph, or are fabricated to the dimensions of ASME B16.5 or other

acceptable standards, except that the dimension R is decreased to provide a nut-stop, the fillet radius shallbe as shown in Figures 4.16.3 and 4.16.4 except that:

a) For flanges designed to this paragraph, the thickness of the hub at the large end,1

g , must be the

smaller of 2 nt or 4 ur , but not less than 12 mm (0.5 in.).

b) For ASME B16.5 or other standard flanges, the thickness of the hub at the small end,0

g , shall be

increased as necessary to provide a nut-stop.

4.16.11 Qualification Of Assembly Procedures And Assemblers

Flange joints designed using the Method B bolt load procedure shall be assembled by qualified bolted-jointassemblers. Bolted joints designed for flange assembly efficiencies, 6, greater than 0.75 (see Table 4.16.7)

shall be assembled and bolted-up in accordance with a written procedure that has been qualified by test toachieve the specified assembly efficiency. The procedure shall address need for through hardened washers.Bolted-joint assemblers shall be qualified by test of a prototype assembly to demonstrate that they can apply

the qualified procedure and achieve the specified assembly efficiency.


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4.16.12 Nomenclature

gA is the gasket contact area.

A is the outside diameter of the flange or, where slotted holes extend to the outside of theflange, the diameter to the bottom of the slots.

bA is the cross-sectional area of the bolts based on the smaller of the root diameter or the least

diameter of the unthreaded portion.mA is the total minimum required cross-sectional area of the bolts.

pA is the partition plate gasket contact area.

a is the exponent of the gasket assembly-loading curve used to compute the gasket stress

yaS .

B is the inside bore of the flange, when 120B g7 , the Designer may use 1B for B in the

equation for the longitudinal stress.*B is the inside diameter of the reverse flange.

1B is 1B g2 for loose type flanges and for integral type flanges that have a value of fless than

1.0, although a minim value of 1.0f # is permitted, 0B g2 for integral type flanges when

1.0f 3 .

b is the effective gasket contact width.

0b is the basic gasket seating width.

C is the bolt circle diameter.

ulC is the conversion factor for length, 1.0ulC # for US Customary Units and 25.4ulC # for

Metric Units.

usC is the conversion factor for stress, 1.0usC # for US Customary Units and

6.894757 03usC E# , for Metric Units.

C is the bolt circle diameter.

d is the flange stress factor.rd is the flange stress factor d for a reverse type flange.

ygE is the Modulus of Elasticity at the gasket seating load case temperature.

yoE is the Modulus of Elasticity at the operating load case temperature.

e is the flange stress factor.

re is the flange stress factor e for a reverse type flange.

6 is the assembly efficiency, or the ratio of the minimum to average gasket stress, which

accounts for variations in the bolt load and gasket stress based on the method of jointassembly.

F is the flange stress factor for integral type flanges.

F is the value of the external net-section axial force.LF is the flange stress factor for loose type flanges.

sF is the moment factor used to design split rings, 1.0sF # for solid rings, 2.0sF # for solid

rings, and 0.75sF # for solid rings (see paragraph 4.16.8).

f is the hub stress correction factor for integral flanges.

G is the location of the gasket reaction.


13/44


bG is the gasket property used to describe the assembly loading curve, bG equals the gasket

stress when 1.0pT # .

cG is the outside diameter of the gasket contact area.

sG is the gasket property used to describe the unloading curve, sG equals the gasket stress

when 1.0p

T # .

0g is the thickness of the hub at the small end.

1g is the thickness of the hub at the large end.

H is the total hydrostatic end force.

DH is the total hydrostatic end force on the area inside of the flange.

GH is the gasket load for the operating condition.

pI is the difference between the total hydrostatic end force and hydrostatic end force on the

area inside the flange.

h is the hub length.

Dh is the moment arm for load DH .

Gh is the moment arm for load GH .

Th is the moment arm for load TH .

I is the bending moment of inertia of the flange cross-section.

pI is the polar moment of inertia of the flange cross-section.

J is the flange rigidity index.

K is the ratio of the flange outside diameter to the flange inside diameter.

RK is the rigidity index factor.

k is the exponent of the unloading curve.

L is the flange stress factor.

rL is the flange stress factor L for a reverse type flange.

E is the absolute value of the external net-section bending moment.

g is the flange design moment for the gasket seating condition.

o is the flange design moment for the operating condition.

oe is the component of the flange design moment resulting from a net section bending moment

and/or axial force.m is the gasket factor.

N is the gasket contact width.: is Poissons ratio.

P is the design pressure.

tP is the test pressure.

Q is the factor that varies between 0.0 and 1.0 that adjusts the overall effect of nonuniform

gasket stress caused by an external net-section bending moment relative to an equivalentnet-section axial load.

r is a radius to be at least 10.25g but not less than 5 mm (0.1875 in.).

ur is the radius of the undercut on a flange with nut stops.

bgS is the membrane stress intensity limit from Part 3 for the bolt at the gasket seating

temperature.

boS is the membrane stress intensity limit from Part 3 for the bolt at the design temperature.


14/44


cS is the maximum permissible gasket stress to avoid tightness performance damage.

fgS is the membrane stress intensity limit from Part 3 for the flange at the gasket seating

temperature.

foS is the membrane stress intensity limit from Part 3 for the flange at the design temperature.

lS is the minimum permitted value of the operating gasket stress.

moS is the design gasket operating stress.

1mS is the minimum gasket operating stress to meet the required joint tightness.

2mS is the average operating gasket stress after the design pressure and external loads are

applied.

ngS is the membrane stress intensity limit from Part 3 for the nozzle neck, vessel, or pipe at the

gasket seating temperature.

noS is the membrane stress intensity limit from Part 3 for the nozzle neck, vessel, or pipe at the

design temperature.

sS is the gasket stress developed when contact is initiated with a compression limit device, or a

stress associated with a tightness limit.

yaS is the design gasket assembly stress.

HS is the flange hub stress.

RS is the flange radial stress.

TS is the flange tangential stress.

1TS is the flange tangential stress at the outside diameter of a reverse flange.

2TS is the flange tangential stress at the inside diameter of a reverse flange.

T is the flange stress factor.

cT is the tightness class factor.

PT is the tightness parameter.

PaT is the assembly tightness.

maxPT is the gasket property obtained by test that determines the maximum usable tightness.

minPT is the minimum required tightness to assure satisfactory leakage performance is achieve

able in operation for the specified tightness class.

rT is the flange stress factor T for a reverse flange.

t is the flange thickness including the facing thickness and groove depth if not exceeding 2mm (0.0625 in.); otherwise, the facing or groove depth is not included in the flangethickness.

nt is the nominal thickness of the shell, pipe, or nozzle to which the flange is attached.

x

t is0

2g when the design is calculated as an integral flange, or two times the minimum

required thickness of the shell or nozzle wall when the design is based on a loose flange, butnot less than 6 mm ( 0.25 in.).

U is the flange stress factor.

rU is the flange stress factor U for a reverse type flange.

V is the flange stress factor for integral type flanges.

LV is the flange stress factor for loose type flanges.

amW is the minimum assembly bolt load.


15/44


gW is the design bolt load for the gasket seating condition.

moW is the minimum required operating bolt load used to establish the design bolt load.

oW is the design bolt load for the operating condition.

omW is the minimum operating bolt load.

w is the width of the nubbin.

Y is the flange stress factor.rY is the flange stress factor Y for a reverse type flange.

Z is the flange stress factor.


16/44


4.16.13 Tables

Table 4.16.1 Representative Tightness Classes And categories For Determining The Bolt LoadsUsing Method B

Tightness Class Tightness ClassFactor cT

Leak ratelbHe/hr/in diameter

Leak rate,MgHe/sec/mm diameter

1 0.1 1/25 1/5

2 1 1/2500 1/500

3 10 1/250000 1/50000


17/44


Table 4.16.2 Gasket Factors For Determining The Bolt Loads Using Method A

Gasket Material

GasketFactor,

m

Min.DesignSeatingStress y,

(psi)

Column inTable4.16.5

FacingSketch In

Table 4.16.5

Self-energizing types (O rings, metallic,elastomer, other gasket types considered as self-sealing)

0 0 --- ---

Elastomers without fabric or high percent ofasbestos fiber:

; Bellow 75 A Shore Durometer; 75 A or higher Shore Durometer

0.501.00

0.501.00

II (1a), (1b),(1c), (1d),(4), (5);

Asbestos with suitable binder for operatingconditions:

; 1/8 inch thick; 1/16 inch thick; 1/32 inch thick

2.002.753.50

1,6003,7006,500

II (1), (1b),(1c), (1d),

(4), (5)

Elastomers with cotton fabric insertion 1.25 400 II (1a), (1b),(1c), (1d),

(4), (5)

Elastomers with asbestos insertion (with orwithout wire reinforcement):

; 3-ply; 2-ply; 1-ply

2.252.503.75

2,9002,9003,700

II (1), (1b),(1c), (1d), (5)

Vegetable fiber 1.75 1,100II (1a), (1b),

(1c), (1d),(4), (5)

Spiral-wound metal, asbestos filler

; Carbon steel; Stainless steel, Monel, and nickel-base

alloy

2.503.00

10,00010,000

II (1a), (1b)

Corrugated metal, asbestos inserted, orcorrugated metal, jacketed asbestos filled:

; Soft aluminum; Soft copper or brass; Iron or soft steel; Monel or 4% - 6% chrome

; Stainless steels and nickel-base alloys

2.502.753.003.253.50

2,9003,7004,5005,5006,500

II (1a), (1b)

Corrugated metal:

; Soft aluminum

; Soft copper or brass; Iron or soft steel; Monel or 4% - 6% chrome


2.75

3.003.253.503.75

3,700

4,5005,5006,5007,600

II (1a), (1b),(1c), (1d)


18/44


Table 4.16.2 Gasket Factors For Determining The Bolt Loads Using Method A

Gasket Material

GasketFactor,

m

Min.DesignSeatingStress y,

(psi)

Column inTable4.16.5

FacingSketch In

Table 4.16.5

Flat metal, jacketed asbestos filled:; Soft aluminum; Soft copper or brass; Iron or soft steel; Monel; 4% - 6% chrome


3.253.503.753.503.753.75

5,5006,5007,6008,0009,0009,000

II (1a), (1b),(1c), (1d), (2)

Grooved Metal:



3.253.503.753.75

4.25

5,5006,5007,6009,000

10,100

II (1a), (1b),(1c), (1d),

(2), (3)

Sold flat metal:



4.004.755.506.006.50

8,80013,00018,00021,80026,000

I (1a), (1b),1c), (1d), (2),(3), (4), (5)

Ring joint:

; Iron or soft steel; Monel or 4% - 6% chrome

; Stainless steel and nickel-base alloys

5.506.006.50

18,00021,80026,000

I (6)


19/44


Table 4.16.3 Gasket Factors For Determining The Bolt Loads Using Method B

Gasket MaterialbG

(2, 14)

a

(2,14)sG PmaxT

(4,13)

lS

(5)

cS

(6)

Notes

Self-energizing gasketsSpring energized gasket

500 0 1e-10 500500

3, 83, 8

Compressed elastomers reinforcedwith asbestos fibers (


20/44



Gasket MaterialbG

(2, 14)

a

(2,14)sG PmaxT

(4,13)

lS

(5)

cS

(6)

Notes

Spiral wound stainless steel:

; Asbestos filled

; Flexible graphite filled; Flexible graphite filled soft; PTFE filled; PTFE filled soft; Mica filled

3400

2300600

450067202600

0.300

0.2370.3900.1400.1000.230

93

132

709815

500

48002000

14200200

3700

900

900900900900900

3, 8

12

12

Spiral wound stainless steel with innerring:

; Asbestos filled; Flexible graphite filled; Flexible graphite filled soft; PTFE filled; PTFE filled soft

; Mica filled

34002530231

22802600

0.3000.2410.556

0.1900.230

934

0.3

6715

5002800

54003700

900900900900900900

3, 8

157

12

1215

Spiral wound Monel or Ni alloy:

; Asbestos filled; Flexible graphite filled; Flexible graphite filled soft; PTFE filled

34002300600

4500

0.30.2370.3900.14

93132

70

50048002000

14200

900900900900

3, 81010

10, 1210

Spiral wound Monel or Ni alloy withinner ring:

; Flexible graphite filled; Flexible graphite filled soft; PTFE filled

2530231

2280

0.2410.5560.19

40.367

2800

5400

900900900

3, 8

1010, 12

10

Corrugated metal jacketed with softinsert:

; Soft copper or brass; Soft steel or iron; Monel or 4-6% Cr; Stainless steel or 12% Cr

42508500

0.2140.134

230230

100200

1350135013501350

SySySySy

11

7

Corrugated metal sheet (0.015-0.025inch):

; Soft Aluminum; Soft copper or brass; Soft steel or iron; Monel or 4-6% Cr; Stainless steel or 12% Cr; Graphite on stainless steel;

Graphite on stainless steel soft

15003000

4700540.338.72

0.240.16

0.150.3640.697

430115

13022

2570054200

56001300013000

13501350135013501350900900

SySySySySy

3200032000

Flat metal jacketed with soft insert:

; Soft Aluminum; Soft copper or brass; Soft steel or iron; Monel or 4-6% Cr; Stainless steel or 12% Cr

1800290029002900

0.350.230.230.23

15151515

600230023002300

13501350135013501350

320032003200

11

1010


21/44



Gasket MaterialbG

(2, 14)

a

(2,14)sG PmaxT

(4,13)

lS

(5)

cS

(6)

Notes

Soft flat metal:

; Soft Aluminum

; Soft copper or brass; Soft steel or iron; Monel or 4-6% Cr; Stainless steel or 12% Cr

1525

5000

0.24

0.133

200

258

24000

10600

1350

1350135013501350

Sy

SySySySy

Solid flat metal (1/8 inch nubbinfacing):

; Soft Aluminum; Soft copper or brass; Soft steel or iron; Monel or 4-6% Cr; Stainless steel or 12% Cr

240012000

0.200.11

25065

18700400

13501350135013501350

SySySySySy

Notes:1. Binder, fillers and fibers must be suitable for service fluid and conditions over the proposed service lifeof the gasket.

2. See paragraph 4.16.5.3 for validity of temperature for the constant sG

3. Gasket constants are valid for only for designs that employ a compression limit feature such as agroove or gage rings.

4. Credit for additional tightness is not permitted for Pa PnT T0 . An asterisk (*) indicated that hardening

limitsmaxP

T .maxP

T is the lesser of PsT (Hardening) or PuT (Max test value) unless higher values

verified by ROTT test procedure

5. The stress moS shall be greater than the value lS unless verified by test ASTM ROTT for the gasket

under consideration.

6. The gasket stress cS represents a maximum acceptable value that shall not be exceeded unless it isconfirmed by test the tightness performance will not be impaired by a greater stress. The Designer

shall establish an appropriate value of cS where none is given in this table. For metal gaskets yS

indicates the yield strength of the of the gasket material at the design temperature.

7. Values of bG , a , sG imputed from similar product data in the case of spiral wound gaskets and in the

case of jacketed or solid metals from metal to metal type comparisons.

8. cS is limited by the yield strength of the respective compression stops

9. cS is indicated by interpretation of ROTT Test Data and has not been determined by a tightness

crush test. Use this data or documented crush test data10. These constants are based on data for gaskets with stainless steel because no nickel or Monel data is

available.11. Insert must be suitable for service conditions over its life.

12. Constants are for lower pressure applications where 10,000ya

S psi/

13. maxPT to be determined by ROTT Test.

14. Where data is not given for bG , a , sG , the gasket manufacturer shall provide gasket data certified by

ROTT test.15. These constants are based on data for same filler gaskets without internal ring because no data is

available for same gaskets with internal ring.


22/44


Table 4.16.4 Recommended Gasket Contact Width For Determining The Bolt Loads UsingMethod B

Gasket Contact Width, N

Gasket Outside DiameterGasket Type

< 150 mm

(6 inch)

< 300 mm

(12 inch)

< 600 mm

(24 inch)

< 900 mm

(36 inch)

900 mm (36inch) and

Over

Sheet Gaskets IncludingLaminated Sheets Gaskets WithOr Without A Metal Core

9 mm

(3/8 inch)

12 mm

(1/2 inch)

16 mm

(5/8 inch)

16 mm

(5/8 inch)

19 mm

(3/4 inch)

Preformed Composite GasketsIncluding Spiral Wound, Jacketed,

And Solid Flat Metal Gaskets

6 mm

(1/4 inch)

9 mm

(3/8 inch)

12 mm

(1/2 inch)

16 mm

(5/8 inch)

16 mm

(5/8 inch)


23/44


Table 4.16.5 Effective Gasket Width For Determining The Bolt Loads Using Method A

Basic Gasket Seating Width ob FacingSketch

Facing Sketch Detail (Exaggerated)

Column 1 Column 2

1N N

1BSee Note 1

NN

2

N

2

N

1C T

N

W

w


24/44


Table 4.16.6 Effective Gasket Width For Determining The Bolt Loads Using Method B

FacingSketch

Facing Sketch Detail (Exaggerated) Basic Gasket Seating Width ob

1 N N

N

2w < N/2

W

N0.4 mm (1/64 in) Nubbin

( )w T N2 /

3

W

4

w


25/44


Table 4.16.7 Assembly Efficiencies For Determining The Bolt Loads Using Method B

Assembly Efficiency,6

Bolt Preload Control Method Bolt Load Variation fromMean

0.75Power impact, lever striker (manual or power)

wrench

50%Over

0.85 Accurately applied torque 3%< 30% 50%to< <

0.95Simultaneous multiple application of directtension to three or more bolts

10% 30%to< <

1.0Direct measurement of stud stress or strain, orthe simultaneous hydraulic tensioning of allbolts

10% or less<

Notes:1. Assembly efficiency refers to the uniformity of gasket stress, tightness and leak rate variations around

the circumference. Assembly efficiency decreases with scatter in bolt load and is affected by frictional

variations and elastic interaction where elastic interaction depends on the stiffness of the flange, bolt,and gasket system. Significant bolt load losses as high as 50% have been observed even when usingcontrolled torque or tensioning of bolts. (WRC Bulletin 406, Bolted Flange Assembly: Preliminary ElasticInteraction Data and Improved Bolt-up Procedures.)

2. Joint tightness is also reduced by not operating at the target mean bolt load. This effect is not included inthe assembly efficiencies of this table.

3. For joints using compression stops of for O-ring gaskets, as assembly tightness of 1.0 can be used when

full stop contact is assumed by the design bolt-up procedures (s ya

S S# ). In determining the minimum

assembly bolt load amW , set 0.906# and calculate am s g W S A 6# .

4. The assembly efficiency values given in this table are recommended and are not mandatory.


26/44


Table 4.16.8 Moment Arms For Flange Loads For The Operating Condition

Flange Type Dh Th Gh

Integral Type Flanges1

2

g

R 2 1

2

GR g h2 2 2

C G,

Loose Type Flanges2

C B,

2

D Gh h2 2

C G,

Integral Reverse TypeFlanges

1 2

2

oC g g B2 , , 1

2 2

B GC

2! ",$ %

& '

2

C G,

Loose Reverse Type Flanges2

C B,

1

2 2

B GC

2! ",$ %

& '

2

C G,


27/44


Table 4.16.9 Flange Moments Of Inertia

Flange Type I pI

Integral Type Flangewith a Hub

20.3498 o oLg h BI

V

#

Loose Type Flange

with a Hub

20.3498 o o

L

Lg h B

I V#

p AB CDI K K# 2

where

( )4

3 1 10.21 13 12

B BAB A B

A A

B BK A B

A A

* +! "! " = >4 5$ %# , , ? @$ %$ %4 5& ' A B& '- .

( )4

3 1 10.21 13 192

DG DGCD C DG

C C

D DK C D

C C

* +! "! " = >4 5$ %# , , ? @$ %$ %4 5& ' A B& '- .

with

2R

BA ,#

,A R B R

A A B t if A t# # 3

,A B R RA t B A if A t# # 7

,C DG avg avg C h D G if h G# # 3

,C avg DG avg

C G D h if h G# # 7

Integral or LooseType Flange without aHub

3 ln

6

Bt KI#

4

3 1 1

0.21 13 12p R

R R

t t

I A t A A

* +! "! " = >

4 5$ %# , , ? @$ %$ %4 5& ' A B& '- .

where

2R

A BA

,#


28/44


Table 4.16.10 Flange Stress Factor Equations

Flange Type Stress Factors

Integral TypeFlange, LooseType Flange

with a Hub,ReverseFlanges

( )

( ) ( ) ( ) ( )( ) ( )

( )( ) ( ) ( )

3

2 2

3 3

22

0.897697 0.297012ln 9.5257 10 ln

0.123586 ln 0.0358580 ln 0.194422 ln ln

0.0181259 ln 0.0129360 ln

0.0377693 ln ln 0.0273791 ln ln

g h

g h g h

g h

g h g h

F X X

X X X X

X X

X X X X

,# , 2 2

2 , ,

2 ,

2

2

2

23

3 2

0.1 0.5

0.227914 0.3444100.500244 1.87071 2.49189

0.1899530.873446 1.06082 1.49970 0.719413

h

h h

g g

h h hh

g g g g

For X

V X XX X

X X XX

X X X X

/ /

# 2 , , 2 2

2 , , 2

2 2

3 3 2 2

0.5 2.0

0.135977 0.0461919 0.560718 0.05298290.0144868

0.244313 0.113929 0.00928265 0.0266293 0.217008

h

g h g h

g h g h g h g h

For X

VX X X X

X X X X X X X X

7 /

# , , , 2 2

2 , , ,

2

2 3

3

2 3

0.0927779 0.0336633 0.964176

0.0566286 0.347074 4.18699max 1.0,

1 5.96093(10 ) 1.62904

3.49329 1.39052

g g

h h h

g h

h h

X X

X X Xf

X X

X X

,

* += >! ", 2 24 5C C$ %

$ %4 5C 2 , C& '# 4 5? @! ", 2 24 5C C$ %4 5C C$ %24 5& 'A B- .


29/44




Loose TypeFlanges ( ) ( ) ( )

( ) ( ) ( )

( ) ( ) ( )

( ) ( )( )

2

2

2

2

0.941074 0.176139 ln 0.188556 ln 0.0689847 ln

0.523798 ln 0.513894 ln ln

1 0.379392 ln 0.184520 ln 0.00605208 ln

0.00358934 ln 0.110179 ln ln

g h g

h g h

L

g h g

h g h

X X X

X X X

FX X X

X X X

* +2 , 2 24 54 5,- .

# * +2 2 , ,4 54 52- .

8 9 ( )

( ) ( )

( ) ( )

2

4

0.1 0.25

ln 6.57683 0.115516 1.39499 ln

0.307340 ln 8.30849 2.62307 ln

7.035052(10 )0.239498 ln 2.96125 ln

h

L g h g

g h g

h g g

h

For X

V X X X

X X X

X X XX

,

/ /

# , 2 2

, 2 2

, 2

( ) ( )

( )( )

( )

( )

2

2

3

3 2

2

0.25 0.50

1.33458 0.4171351.56323 1.80696 ln 0.276415 ln

1.39511 ln 0.402096 ln0.09435970.0137129 ln

0.101619 ln

h

L g g

h h

g g

g

h h h

g

h

For X

V X XX X

X XX

X X X

X

X

7 /

# , , 2 2 2

2 2 , ,

2 2

3 3 2 2

0.50 1.0

0.0763597 0.102990 0.725776 0.1606030.0213643

0.0918061 0.472277 0.0873530 0.527487 0.980209

h

L

g h g h

g h g h g h g h

For X

VX X X X

X X X X X X X X

7 /

# , , 2 2 , ,

2 2 2 ,D D D

3

2 2

3 3 2 2

1.0 2.00.220518 0.0602652 0.619818 0.223212

7.96687(10 )

0.421920 0.0950195 0.209813 0.158821 0.242056

h

L

g h g h

g h g h g h g h

For X

VX X X X

X X X X X X X X

,7 /

# , 2 2 , 2

2 2 , ,D D D

1.0f #


30/44




Notes:1. For integral and loose type flanges

1

0g

gX

g# (4.16.49)

0

h

hX

Bg# (4.16.50)

2. For reverse type flanges

1

0

g

gX

g# (4.16.51)

0

h

hX

Ag# (4.16.52)


31/44


Table 4.16.11 Flange Stress Factors Equations Involving The Parameter K

Flange Type Stress Factors Involving The Parameter K

Integral and Loose TypeFlanges

AK

B#

2

10

2

log10.66845 5.71690

1 1

K KY

K K

* +! "# 24 5$ %

, ,& '- .

( )

( ) ( )

2

10

2

1 8.55246 log 1

1.04720 1.9448 1

K KT

K K

2 ,#

2 ,

( )

( )( )

2

10

2

1 8.55246 log 1

1.36136 1 1

K KU

K K

2 ,#

, ,

( )( )

2

2

1

1

KZK

2#,

31te t

LT d

2# 2

0

Fe for Integral Type Flanges

Bg#

0

LF

e for Loose Type FlangesBg

#

2

o oUg Bg d for Integral Type Flanges

V#

2

o o

L

Ug Bg d for Loose Type Flanges

V#


32/44


Table 4.16.11 Flange Stress Factors Equations Involving The Parameter K

Flange Type Stress Factors Involving The Parameter K

Reverse Type Flanges The parameters K, T , U , Y , and Z are determined using the equationsfor Integral and Loose Type Flanges with:

*

AK B#

Then, the reverse flange parameters are computed as follows:

r rY YE#

( )

( )

0.3

0.3r r

ZT T

ZE

2#

,

r rU UE#

31rr

r r

te t

L T d

2# 2

1 0.668( 1)1r

K

K YE

2* +# 24 5- .

0

r

Fe for Integral Type Flanges

Ag#

0

Lr

Fe for Loose Type Flanges

Ag#

2r o o

r

U g Ag d for Integral Type FlangesV

#

2

r o o

r

L

U g Ag d for Loose Type Flanges

V#


33/44


Table 4.16.12 Flange Stress Equations

Stress EquationsFlange Type

Operating Condition Gasket Seating Conditions

Integral Type Flange

21

o

H

fM

S Lg B#

( )2

1.33 1 oR

te MS

Lt B

2#

2

oT R

YMS ZS

t B# ,

2

1

g

H

fM

S Lg B#

( )2

1.33 1 gR

te MS

Lt B

2#

2

g

T R

YMS ZS

t B# ,

Loose Type Flange

2

oT

YMS

t B#

2

g

T

YMS

t B#

Integral Reverse TypeFlange 2 *1

oH

r

fMSL g B

#

( )2 *

1.33 1r oR

r

te MS

L t B

2#

( )

( )1 2 *

0.67 1

1.33 1

R rr oT

r

ZS teY MS

t B te

2# ,

2

( )

( )

2

2 2 *2

2 0.67 1

1

r oT r

r

K teS Y

t BK L

* +24 5# ,

,4 5- .

2 *

1

g

H

r

fMSL g B

#

( )2 *

1.33 1r gR

r

te MS

L t B

2#

( )

( )1 2 *0.67 1

1.33 1

r g R r

T

r

Y M ZS teS

t B te

2# ,

2

( )

( )

2

2 2 *2

2 0.67 1

1

gr

T r

r

K teS Y

t BK L

* +24 5# ,

,4 5- .

Loose Reverse TypeFlange 2 *

r oT

Y MS

t B#

2 *

r g

T

Y MS

t B#


34/44


Table 4.16.13 Flange Stress Acceptance Criteria

Stress Acceptance CriteriaFlange Type


Integral Type Flange or

Loose Type Flange witha Hub

min 1.5 , 2.5 (1)H fo noS S S* +/

- . 1.5 (2)

H foS S/

1.0 (3)H fo

S S/

R fo

S S/

T foS S/

( )2

H R

fo

S SS

2/

( )2

H T

o

S SS2 /

min 1.5 , 2.5 (1)H fg ngS S S* +/

- . 1.5 (2)

H fgS S/

1.0 (3)H fg

S S/

R fg

S S/

T fgS S/

( )2

H R

g

S SS

2/

( )2

H T

fg

S SS2 /

Loose Type FlangesT foS S/

T fgS S/

Integral Reverse TypeFlanges

1.5H foS S/

R fo

S S/

1T fo

S S/

( )2

H R fo

S SS

2

/

( )12

H T

o

S SS

2/

2T foS S/

1.5H fgS S/

R fg

S S/

1T fg

S S/

( )2

H R g

S SS

2

/

( )12

H T

fg

S SS

2/

2T fgS S/

Loose Reverse TypeFlanges

T foS S/

T fgS S/

Notes:1. For integral flanges with hubs welded to a nozzle neck, pipe, or vessel shell2. For loose type flanges with a hub

3. For flanges made of cast iron.


35/44


Table 4.16.14 Flange Rigidity Criterion

Rigidity CriterionFlange Type


Integral Type Flange 20 0

52.141.0o

yo R

VMJ LE g K Bg# /

20 0

52.141.0

g

yg R

VMJ

LE g K Bg# /

Loose Type Flangeswith Hubs 2

0 0

52.141.0L o

yo R

V MJ

LE g K Bg# /

2

0 0

52.141.0

L g

yg R

V MJ

LE g K Bg# /

Loose Type Flangeswith Hubs ( )3

109.41.0

ln

o

yo R

MJ

E t K K# /

( )3109.4

1.0ln

g

yo R

MJ

E t K K# /

Notes:

1. For an integral type flange, 0.2RK # unless another values is specified by the Purchaser.2. For a loose type flange with or without a hub, 0.3

RK # unless another values is specified by the

purchaser.


36/44


4.16.14 Figures

W

R

Ch

D

HD

g1

B

t

A

HG

hG

G

hT

HT

Gasket

g1/2g0

h

W R

r1

C

hD

HD

g1/2

B

g1= g

o

tA

HG

hG

G

hT

HT

Gasket

(a) Integral Flange Without A Hub

(b) Integral Flange with go=g

1

Figure 4.16.1 Integral Type Flanges


37/44


Where Hub Slope Adjacentto Flange Exceeds 1:3,

Use Hub Type 2 or 3

go

Slope exceeds 1:3

g1

h

1.5 go(min.)

C WeldL

go

Slope exceeds 1:3

g1

h

1.5 go(min.)

Slope 1:3 (max.)

(b) Hub Type 2 (c) Hub Type 3

go

W R

r1

C

hD

Slope 1:3 (max.)

HD

g1/2

B

g1

t h > 1.5goA

HG

hG

G

hT

HT

Gasket

(a) Hub Type 1

C WeldL

Figure 4.16.2 Integral Type Flanges With A Hub


38/44


g1

Inside

Diameter

r = 1/4

In. 3/16 In.

go

Nut Stop Diameter

g1

Inside

Diameter

r = 1/4

In. 3/16 In.

goNut Stop Diameter

g1

Inside

Diameter

r = 1/4

In.

Nut Stop Diameter

3/16 In.

g1

Inside

Diameter

r = 1/4

In.3/16 In.

F

Nut Stop Diameter

For Integrally

Reinforced Nozzles,

Min.= Nut Height + 1/4 In.

(a) Detail A (b) Detail B

(c) Detail C(d) Detail D

Figure 4.16.3 Integral Type Flanges With Nut Stops Diameter Less Than Or Equal To 18 Inches


39/44


g1

Inside

Diameter

r = 3/8 In.

5/16 In.

Figure 4.16.4 Integral Type Flanges With Nut Stops Diameter Greater Than 18 Inches


40/44


W

r

C

hD

HD

go

B

g1

t hA

HG

hG

G

hT

HT

Gasket

(a) Loose Flange With A Hub

W C

hD

HD

B

tA

HG

hG

G

hT

HT

Gasket

(b) Loose Flange Without A Hub

Figure 4.16.5 Loose Type Flanges


41/44


Notes (Loose Type Flanges):

(1) For Hub Tapers 6 or Less, Use go = g1

t

go

To Be Taken At Midpoint Of Contact

Between Flange And LapIndependent Of Gasket Location

g1

W C

hD

HD

r

A

G

hGor h

T

HG+ H

T

Gasket

h

Optional Hub

Figure 4.16.6 Loose Type Lap Joint Type Flanges


42/44


W

r

C

hD

HD

go

B

g1

t hA

HG

hG

G

hT

HT

Gasket

(a) Loose Flange With A Hub

W C

hD

HD

B

tA

HG

hG

G

hT

HT

Gasket

(b) Loose Flange Without A Hub

Figure 4.16.7 Loose Type Threaded Flanges


43/44


HG

B*

W

go

t

h

Shell

AB

C

G

hG

g1

hD

hT

HT

HD

HG

B*

W

t

Shell

A = B

C

G

hG

hD

hT

HT

HD

(a) Integral Type Reverse Flange

(b) Loose Type Reverse Flange

Figure 4.16.8 Reverse Flanges


44/44


Gc- OD Contact Face

b

HG

hG

G

Method A - For bo

> 6 mm (1/4 in.) Method A - For bo

< 6 mm (1/4 in.)

HG

hG

CL

G

Gasket Face

Method B - For bo

> 12 mm (1/2 in.) Method B - For bo < 12 mm (1/2 in.)

Figure 4.16.9 Effective Gasket Seating Width

Documents

FlangedJoints