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Flange Design (As per ASME Section VIII Div.1, Appendix-2 Type of Flange : Integral (As per A2-4 (a) (2) - (Fig. 2-4 (5)) Flange material : SA 350 Gr. LF2 Bolt Material : SA 193 Gr .B7 Description Equation Symbol Value Unit Remarks Size of the Flange 30 in Internal Design presure P 9.4 Mpa Internal design temperature 82 ͦ ͦ ˚C Corrosion allowance CA 0 mm Gasket outside diameter Go 844.55 mm Gasket inside diameter Gi 793.75 mm Width used for calculating 'bo' N 25.4 mm Ref. Table 2-4 Basic gasket seating width N/2 bo 12.7 mm Ref. Table 2-5.2 Conversion factor Cb 2.5 For SI unit Effective gasket seating width Cb* √bo b 8.909264841 mm Ref. Table 2-5.2 Diameter at location of gasket load reaction Go-2b for bo > 6 G 826.7314703 mm Total hydrostatic end force 0.785 G ² P H 5043435.254 N Gasket factor m 3 Ref. Table 2-5.1 Total joint-contact surface compression load 2b x 3.14 G*m*P Hp 1304412.918 N Minimum required bolt load for operating condition H+H p Wm1 6347848.172 N Gasket or joint contact surface seating load y 69 MPa Ref. Table 2-5.1 Minimum required bolt load for gasket seating 3.14 * b*G*y Wm2 1595824.314 N Allowable bolt stress at design temperature Sb 172 MPa Rerf. Sec.2 Par-D Allowable bolt load at atmospheric temperature Sa 172 MPa Rerf. Sec.2 Par-D Total cross sectional area of bolts required for operating condition W m1 /S b Am1 36906.09402 mm2 Total cross sectional area of bolts required for gasket seating W m2 /Sa Am2 9278.048338 mm2 Total required cross sectional area of bolts Greater (A m1 , A m2 ) Am 36906.09402 mm2 Nominal bolt diameter a 50.8 mm Threads per inch n 4.5 Total cross sectional area available in the bolt 0.7854 (a-(0.9743/n))2 Ab 1611.755446 mm2 Number of bolts Nb 28 Total available area in all bolts Ab*Nb Atb 45129.15248 mm2 Safe Flange thickness t 192 mm Maximum bolt spacing 2a + 6t/(m+0.5) Bsmax 430.7428571 mm Flange design bolt load (for operating condition) W m1 W 6347848.172 N Flange design bolt load (gasket seating) (Am+Ab)Sa / 2 W 3312535.054 N Bolt Circle diameter C 1022.35 mm Value for Flange rotation at sealing surface (C-G)/2 hG 97.80926484 mm to be kept minimum Outside diameter of the flange A 1130.3 mm Inside diameter of the flange B 737 mm use 'B' for stress calc. Hydrostatic end force on area inside of flange 0.785*B^2*P HD 4008044.051 N Joint efficiency Ej 1 Ref. UW-12 Maximum allowable stress value S 138 Mpa Rerf. Sec.2 Par-D Hub thickness required due to internal pressure P(B/2) / S.E j -0.6P tr 26.17029314 mm Ref. UG-27 Thickness of hub at back of the flange g1 30 mm > tr, OK Radial distance from bolt circle to point of intersection of hub & back of flange (C-B/2) - g1 R 112.675 mm Radial distance from bolt circle to circle on which HD acts R + 0.5 g1 hD 127.675 mm Ref. Table 2-6 Component of moment due to HD H D *h D MD 511727024.2 N.mm Difference in hydrostatic end forces H - H D HT 1035391.203 N Gasket load (Operating) W-H HG 1304412.918 N Radial distance from bolt circle to circle on which HT acts (R + g1 + h G )/2 hT 120.2421324 mm Ref. Table 2-6 Component of moment due to HT H T* h T MT 1035511.445 N.mm Component of moment due to HG H G * h G MG 127583668.5 N.mm Total flange moment (operating) sum of (M D , M T , M G ) Mo 640346204.2 N.mm Sec. 2-6 Total flange moment (gasket seating) W* (C-G)/2 Mo 323996618.4 N.mm Sec. 2-6 Number of bolts Nb 28 Bolt spacing ( π*C)/Nb Bs 114.7074018 mm Bolt spacing check factor 2a+t 293.6 mm If 'Bs' > check factor, multiply Mo by 'Bsc' Proceed with 'Mo' Bolt spacing corrrection factor Max (√(Bs/2a+t), 1) Bsc 1 If applicable
