May I ask about the calculation and verification of the wall thickness for metal pipes under internal pressure?

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This post was last edited by comxp on 2010-3-9 at 15:54. Calculation of wall thickness: S0 = P*D0/(2tΦ+2PY) – where Do is the outer diameter; according to GB-T20801-2006 “Code for Pressure Piping – Industrial Piping” and SH 3059-2001 “General Principles for Selection of Materials for Petrochemical Piping Design”. S0 = P*Di/(2tΦ+P) – where Di is the inner diameter; according to the “Technical Manual for Positive Displacement Compressors”. S0 = P*Di/(2tΦ-P) – where Di is the inner diameter; according to GB150. Stress verification: σ=P*(1.3K^2+0.4)/(K^2-1) – according to the “Technical Manual for Positive Displacement Compressors”; σ=P*(Di+δ)/(2*δ) – according to GB150. If different values are obtained from these calculations, how should one choose? According to SH 3059-2001 “General Principles for Selection of Materials for Petrochemical Piping Design”, when S0 < Do/6, the calculated wall thickness for straight pipes is: S0 = P*D0/(2tΦ+2PY). The actual wall thickness to be used for such pipes is: S = S0 + C. Here, S0 represents the calculated wall thickness in mm； P – Design pressure, MPa ； D0――outer diameter of straight pipe, mm ； t – Allowable stress of the straight pipe material at the design temperature, MPa ； Φ – weld coefficient; for seamless steel pipes, Φ = 1 ； S – Wall thickness of the straight pipe, including additional margin, in mm ； C – Additional margin for straight pipe wall thickness, mm ； Y – Temperature correction coefficient, to be selected according to the table below.