modification thickness of a flange
TRANSCRIPT
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8/11/2019 Modification Thickness of a Flange
1/3
Flange Calculation sheetDoc No Sheet
1/3Bolted flange connections to ASME VIII, div. 2 Appendix 2
Design Basis
Design Code:
ASME Boiler & Pressure Vessel Code - section VIII, Division 1, Appendix 2
Units of calculation
Input Data
Variable Notes
Flange and Flange facing
Pipe Data Nominal Pipe Size
Pipe Schedule
Flange Pressure Rating
Pipe OD (actual)
Pipe wall thickness (Uncorroded)
Length Through Hub
Flange thickness
Bolt circle diameter
Hub Diameter (Largest)
Flange outside diameter
Bolts Bolt Standard
Bolt Size (Specify M-Type , ISO)=
Number of Bolts=
Bolt stress area (per bolt)
Gasket Gasket Type
Gasket diameter , MEAN(RTJ)/OD(RF):
Gasket contact width w(RTJ) or N(RF)
Min. design seating stress
Gasket factor
Design Design Pressure
Conditions Design Temperature
Corrosion Allowance
External Axial Force (strain)
Loads Moment
Moment
Moment
Orientation of flange
Stresses Material
At d esign temperature
At amb ient
Material
At d esign temperature
At amb ient
E Modulus
Conclusion
Flange design is acceptable for listed design pressure 52.6
Bolting design is acceptable for design pressure
Max. operating pressure before failure of flange or bolting is 477.4 psi
Bolting design is acceptable for gasket seating condition
% close of Max.
Oper. Pressure
36" Flange
Max. value
could be
modified(-15.9 mm
from original
88.9mm )
0.0 N/mm
ASME B 31.3
ASME B 31.3
Sa
Sb
Flange
Flange
Sf_oper
Sf_atm
P
ca
Faxial
w or N
y
m
Bolting
Mx
My
Mz
x,y,z
dbolt
nbolt
Abolt
tmax
PCD
X
A
ODpipe
tn
h
t
NPD
Source of data Input
ASME B 31.3
ASME V III, table 2 -4- Pag 380
ASME V III, table 2 -5.1-Pag 381
ASME V III, table 2 -5.1-Pag 381
ASME B 16.5
ASME B 31.3
ASME B 1.1
ASME B 36.10 (Table 1)
ASME B 36.10 (Table 1)
ASME B 16.5 Modified
ASME B 16.5
ASME B 16.5
ASME B 16.5
137.9 N/mm
y
485.0 N/mm
485.0 N/mm
137.9 N/mm
A320 L7 d-
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8/11/2019 Modification Thickness of a Flange
2/3
Flange Calculation sheetDoc No Sheet
2/3Bolted flange connections to ASME VIII, div. 2 Appendix 2
Calculations
Gasket key dimensions
Gasket outside diameter 977.9 mm
Basic gasket seating width b0 = N/2 or w / 8 (RF or RTJ) Table 2-5-2 16.0 mm
Effective gasket seating width b=b0for b0 < 1/4"
or b = 0.5(or 2.52 for metric) * (b0)0.5
for b0 > 1/4" Table 2-5-2 10.1 mm
Gasket load reaction diameter G = mean gasket diameter for b0 < 1/4"
or G = Gasket OD - 2*b for b0 > 1/4" 957.7 mm
Flange values
Thickness of hub at small end g0= tn - ca = 8.0 mm
Thickness of hub at back of flange g1= (X-B)/2 = 8.2 mm
Radial dist. from PCD to large hub diam. R = (PCD-X)/2 = 85.7 mm
Inside diameter of flange B (Corroded ID) = ODpipe- 2 * g0= 898.0 mm
Equivalent Working Pressure using Kellogs Method
Resulting Bending Moment Mres = SQRT(Mx^2+Mz^2) 0 Nmm
Equivalent Pressure Peq = 16 * Mres / ( * G3
) + 4 * Faxial / ( * G2
) 0.00 N/mm
Calculation Design Pressure Pd = P + Peq 1.72 N/mm
Load and Bolt Calculations
Total join t-con tact su rface com pression load Hp= 2 * b * * G * m * P d = 261,436 N
Total hydrostatic end force H = / 4 * G2
* P d= 1,242,002 N
Min. required bolting load for operating conditions Wm1= Hp+H = 1,503,438 N
Min. required bolting load for gasket seating Wm2= * b * G * y = 2,091,184 N
Total required cross-sectional area of bolts Am= greater of W m1/Sbor W m2/Sa= 15,164 mm
Total availab le cross-section al area of b olt s Abolts = 34,684 mm
Flange design bolt load W = 0.5 * ( Am + Abolts ) * Sa = 3,437,040 N
Required bolt rootdiameter= = ( 4 * Am / ( nbolt* ) )0.5
24.6 mm
Flange Moment Calculations
Flange Loads Lever arm Flange Moments
Operating Conditions
HD= / 4 * B2
* P d= 1,091,844 N h D= R + 0.5 * g 1= 89.8 mm MD= HD* hD = 98,053,023 Nmm
HG = Hp = 261,436 N h G= 0.5 * ( PCD - G) = 64.0 mm MG= HG* hG = 16,739,743 Nmm
HT= H - HD= 150,159 N hT = 0.5 * ( R+g 1+hG) = 79.0 mm MT= HT* hT = 11,858,024 Nmm
M0 oper= MD + MG+ MT= 126,650,790 Nmm
Seating Conditions
HG = W = 3,437,040 N hG= 64.0 mm M0 atm= 220,073,687 Nmm
Bolt Spacing= = PCD * SIN( / nbolt) 106.4 mm
Bolt pitch correction factor CF = [bolt_spacing / (2 * d bolt+ 6 * t / ( m + 0.5))]0.5
(or minimum 1.0) 1.00
Flange Factors fr om fi g. 2-7.1 Flange fact or s i nvo lving H/ H_0 o r g 1/ g0 S tr ess formul a f actors
K =A / B 1.303 h0 = (B * go)0,5 84.8 mm = t * e +1 1.774
T 1.796 h / h0 1.839 =4
/ 3 * e * t+1 2.032
U 8.225 g1 / g0 1.025 = / T 0.988
Y 7.484 F 0.899 = t3 / d 4.497
Z 3.867 V 0.517 = + 5.480
f 1.000 m0 =CF * M 0 oper/ B 141,040 N
e = F / ho 0.0106 mm- mG =CF*M0 atm/ B 245,076 N
Poisson's Ratio Assumed = 0.3 d = U / V * h0 * g 02
86,511 mm
36" Flange
Page 2 of 3
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8/11/2019 Modification Thickness of a Flange
3/3
Flange Calculation sheetDoc No
36" Flange
Sheet
3/3Bolted flange connections to ASME VIII, div. 2 Appendix 2
Calculations
SUMMARY OF STRESSES:
Calculated Allowable Accept
Operating
Longitudinal Hub Stress: SH=f * m0 / (* g12
) = 382 N/mm 1.5 * Sf oper= 728 N/mm OK
R adial Flange S tr es s: SR = * m0 / (* t2
) = 10 N/mm Sf oper= 485 N/mm OK
Tangential Flange Stress: ST= m0* Y / ( t2
) - Z * SR= 160 N/mm Sf oper= 485 N/mm OK
C om bined S tr ess : great er of (SH+SR) / 2 or (SH+ST) / 2 = 271 N/mm Sf oper= 485 N/mm OK
Bolt Stress Wm1 / A bolts 43 N/mm Sb 138 N/mm OK
Seating
Longitudinal Hub Stress: SH = f * mG/ ( *g12
) = 663 N/mm 1.5 * Sf atm= 728 N/mm OK
R adial Flange S tr es s: SR= * mG/ ( * t2
) = 17 N/mm Sf atm= 485 N/mm OK
Tangential Flange Stress: ST= mG* Y / ( t2
) - Z * SR= 278 N/mm Sf atm= 485 N/mm OK
C om bined S tr ess : great er of (SH+SR) / 2 or (SH+ST) / 2 = 471 N/mm Sf atm= 485 N/mm OK
Bolt Stress Wm2 / A bolts 60 N/mm Sa 138 N/mm OK
REVERSE CALCULATION - max operating pressure
m0values due to allowable stresses:
Longitudinal Hub Stress: m01 = * g12
* 1.5 * Sf oper/ f = 268,720 N
Radial Flange Stress: m02 = * t2
* S f oper/ = 6,971,100 N
Tangential Flange Stress: m03 = * t2
* S f oper/ ( * Y- * Z ) = 427,154 N
Combined Stress: largest of m04 = 2 * Sf oper/ ( f / ( * g12
) + Y / t2+ / ( * t
2) ) = 231,985 N
m04 = 2 * Sf oper/ ( f / ( * g12) + / ( * t
2) ) = 349,316 N
Select min. m01to m04 m0 = 268,720 N
Max flange moment M0 = = m 0* B / CF = 241,305,119 Nmm
Max operating pressure P=
= 8 * M0 / [ * (B2 * ( PCD - (X + B) / 2) + 8 * b * G * m * (PCD - G) + (G 2 - B2) * (PCD - (G + B)/ 2))] = 3.3 N/mm
Bolting P= = Abolts* Sb/ ( * ( 2 * b * m * G + 0.25 * G2
) ) = 5.5 N/mm
BLIND FLANGE THICKNESS CALCULATION: (3.5.5)
Minimum thickness of flange
(Operating - W=Wm1) eoper= ( 0.3 * G2
* P / ( S f oper) + 1.909 * W m1* hG/ ( S f oper* G ) )0.5
+ ca 38.6 mm
Minimum thickness of flange
(Seating - P=0) eoper= ( 0.3 * G2
* P / ( S f oper) + 1.909 * W * hG/ ( S f oper* G ) )0.5
+ ca 31.6 mm
Max pressure for actual thickness
Operating pmax= (e - ca )2
* S f oper/ ( 0.3 * G2+ 1.909 * * hG* (2 * b * m + 0.25 * G )) 6.4 N/mm
Flange Rigidity Check (According to Appendix S)
Rigidity index J = 52.14 * M0 oper* V / ( * Emod * G 02
* h 0* 0.3) = #DIV/0! #DIV/0!
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