Rectangular Flange Design

Rectangular Flange Design Please note that the abreviations with suffix S are used to denote short side while those with suffix L are used to denote long side Design Calculation has been carried out based on PD 5500 Enquiry Case 5500 / 133 with ASME stress values Design Pressure Pd = 5 N/mm2 Outside Length of long side Al = 2620 mm Outside Length of short side As = 775 mm Inside Length of long side Bl = 2373.5 mm Inside Length of short side Bs = 528.5 mm End Bolt center to center long side Cl = 2520 mm End Bolt center to center short side Cs = 675 mm Gasket O.D. long side Gol = 2440 mm Gasket I.D. long side Gil = 2370 mm Gasket O.D. short side Gos = 600 mm Gasket I.D. short side Gis = 530 mm No. of bolts n = 62 Gasket material = IJA Gasket factor m = 3.75 Design seating stress y = 52 N/mm2 Width of gasket ( same on both sides.) N = Go-Gi/2 Material of flange Yield stress at ambient temperature Allowable stress at design temperature Allowable stress at ambient temperature Youngs Modulus for flange @ Design Material of bolt / studs Bolt size diameter Root Area per bolt / stud Yield stress at ambient temperature Allowable stress at design temperature Allowable stress at ambient temperature When b < 6 mm ; b = bo else b = 2.5 x root (bo) Effective width of gasket Effective width of gasket Gasket reaction long side Gasket reaction short side Hydrostatic End Force Compression Load on gasket Hydrostatic End force applied via shell

Sfy Sfd Sfa Ef

Sby Sbd Sba bo b Gl Gs H HG HD

= = = = = = = = = = = = = = = = = = = = = = = = = =

35 SA-516 70 260 136 138 185000 SA-193 Gr. B7 M42 42 1018.218 695 172 172 N/2 17.5 10.46 Gol-2b 2419 2419.0 .08 8 Gos-2b 579.08 Pd x Gl x Gs 7004204.23 2b x (2Gl + 2Gs) x m x Pd 2352056.52 Pd x Bl x Bs 6271973.75

mm N/mm2 N/mm2 N/mm2 N/mm2

mm2 N/mm2 N/mm2 N/mm2 mm mm mm mm mm N N N

Hydrostatic End force due to pressure

HT

= =

Min. required Bolting Loads Min. Bolt Load for Operating Condition

Wm1

= = = = = = = = = = = = = =

Min. Bolt Load for Gasket Seating Condition

Wm2

Design Flange Load

W

Bolt Area for operating condition

Am1

Bolt Area for gasket seating condition

Am2

Min. Design Bolt Area requirement

Am

Actual Bolt Area

Ab

H-HD 732230.48 N HG+H 9356260.75 2 x (Gl + Gs) x bx y 3261518.374 max(Wm1,Wm2) 9356260.75 Wm1/Sbd 54396.86 Wm2/Sba 18962.32 max.(Am1,Am2) 54396.86 Root area x n 63129.516

N N N mm2 mm2 mm2 mm2

The no. of bolts selected is safe Moment Arms Radial distance from Bolt circle to I.D.

hD

Radial distance from Bolt circle to G.I.D.

hG

Radial distance from Bolt circle to circle at which HT acts

hT

Max. Operating moment

Mop

Maximum Gasket Seating Moment

Matm

Flange thickness calculation check Operating Condition

to

= = = = = = = = = = = =

Gasket Seating Condition

tb

=

Cl-Bl/2 73.25 mm Cl-Gl/2 50.46 mm (2 x Cl x -Bl - Gl)/4 61.855 mm HD x hd + HG x hG + HT x hT 623398965.5 N-mm WxhG 472116917.4 N-mm (6 x Mo)/(Sfd x (2 x (Cl+Cs))-n x d1)^0.5 85.23 mm (6 x Matm)/(Sfa x (2 x (Cl+Cs))-n x d1)^0.5

=

73.63 mm

Min. required thickness

tmon

= =

max(to,tb) 85.23 mm

Selecting flange thickness (excluding R.F.)

tact.

=

125 mm

Pbmax.

=

Max permissible spacing

=

6t x(E/2x10^5)^0.5 + 2Db / (m+0.5) 189 mm

Dimesnion Check for flange design

= = The dimesions are acceptable

(Al-Bl ) - (As-Bs ) = 0 0

Dimesnion Check for flange design

= = The dimesions are acceptable

(Cl-Bl ) - (Cs-Bs ) = 0 0

Additional check Ratio of short to long side Value taken from PD 5500 Min. thickness of welded or bolted flat Min. spacing of bolts / studs Min. thickness of welded or bolted flat with narrow gasket ( at gasket face) Main thickness e1

C As/Al Z t1 Pb

= = = = = =

t2

=

e1 e2

Min. thickness of welded or bolted flat with narrow gasket ( at center)

t2

= = = = = = =

0.41 0.296 1.63 C x Z x a x (Pd / Sfd)^0.5 99.31 mm 100.8 mm ((0.3 x Gs^2 x Pd x Z^2)/Sfa)+((6 x Wm1 x hG)/(n x Pb x Sfo))^0.5 114.71 mm (6xW x hG/n x Pb x Sfa)^0.5 57.31 mm (6xWm1 x hG/n x Pb x Sfo)^0.5 57.73 mm max(e1,e2) 57.73 mm