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Bolt Torque Calculation Guide

The document provides calculations to determine the required torque for bolts connecting a shell flange to a channel flange using an SSPWD gasket. It details the bolt and gasket properties, calculates the internal pressure forces and minimum required bolt load. It then determines the initial required tightening force, total tightening force required to seal the joint, and divides this by the number of bolts to calculate the required torque of 2293.18 N-m. The calculations follow standard formulas to ensure the bolted joint will be properly compressed to seal against the internal pressure of 6.63 N/mm2.

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803 views3 pages

Bolt Torque Calculation Guide

The document provides calculations to determine the required torque for bolts connecting a shell flange to a channel flange using an SSPWD gasket. It details the bolt and gasket properties, calculates the internal pressure forces and minimum required bolt load. It then determines the initial required tightening force, total tightening force required to seal the joint, and divides this by the number of bolts to calculate the required torque of 2293.18 N-m. The calculations follow standard formulas to ensure the bolted joint will be properly compressed to seal against the internal pressure of 6.63 N/mm2.

Uploaded by

shazan
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
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Download as PDF, TXT or read online on Scribd
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31

Part 3 : Bolt Torque Calculations


32

Equipment No. - 155-EE-1015

BOLT TORQUE CALCULATION FOR SHELL FLANGE TO CHANNEL FLANGE


(CONSIDERING SSPWD GASKET)

BOLT DETAIL

MOC of bolt SA193 Gr. B7


Modulus of elasticity of bolting material Eb = 199948 N/mm2
at temperature
Bolt Size = M48
No. of bolts n = 32
Effective length of bolt,mid nut to mid nut lb = 500 mm
Pitch diameter of threads dm = 47.58 mm = 1.87 in.
Root area of 1 bolts = 1342.959 mm2
Root area of n bolts Ab = 42974.688 mm2

GASKET DETAIL

MOC of Gasket = SSPWD


Modulus of elasticity of gasket material Eg = 3924 N/mm2
at temperature
Gasket factor m = 3
Gasket unit seating load y = 69 N/mm2
Thickness of Gasket tg = 6.35 mm
Gaket ID Gid = 1172 mm
Gaket OD God = 1210 mm
Gasket width N = 19 mm
Basic gasket seating width(N/2) bo = 9.5 mm
Effective gasket seating width b = 7.710 mm
{if bo < 6 then b = bo else b = 2.5 x sqrt(bo)}

Diameter at location of gasket load reaction G = 1194.58 mm


(God-2*b)
Actual joint-contact area of gasket(2ʋbG) Ag = 57869.5 mm

Internal Pressure(considering higher of both sideP = 6.63 N/mm2


Total friction factor between bolts/nut K = 0.25
and nut/flange surface

CALCULATION

1 Hydrostatic end force (H)


2
H = ʋ' P/4
= ʌ[A[
= 7430771.19 N

2 Total joint contact-surface compression load (Hp)


Hp = ʌE*P3
= [ʌ[[[[
= 1151023.71 N
33

3 Minimum Required bolt load for gasket seating (Wm2)


Wm2 = ʋbGy
= ʌ[[[
= 1996496.63 N

4 Decreasing compression force in gasket (ȴF)


ȴF = H/[1+ (Ab Eb tg) / (Ag Eg lb)]
= 7430771.19/[1 +{(42974.688 x 199948 x 6.35)/(57869.47 x 3924x500)}
= 5018864.56 N

5 Initial required tightening force(tension) (Fbo)


Fbo = +Sǻ)
= 1151023.71 + 5018864.56
= 6169888.27 N

6 Total tightening force required to seal joint (W)


W = Greater of Fbo and Wm2
= 6169888.27 N
= 1383665.06 lb

7 Required Torque (T)


T = K x W x dm / 12n
= 0.25 x 1383665.05545362 x 1.873 / ( 12 x 32)
= 1687.24 ft-lb
= 2293.180 N-m

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