P = (2 St/D) x F x E x T
P =Design pressure in pounds per square inch (kPa) gauge.
S =Yield strength in pounds per square inch (kPa) determined in accordance with section 255.107 of this Part.
D =Nominal outside diameter of the pipe in inches (millimeters).
t =Nominal wall thickness of the pipe in inches (millimeters). If this is unknown, it is determined in accordance with section 255.109 of this Part. Additional wall thickness required for concurrent external loads in accordance with section 255.103 of this Part may not be included in computing design pressure.
F =Design factor determined in accordance with section 255.111 of this Part.
E =Longitudinal joint factor determined in accordance with section 255.113 of this Part.
T =Temperature derating factor determined in accordance with section 255.115 of this Part.
N.Y. Comp. Codes R. & Regs. Tit. 16 § 255.105