S = [P(1.3D2 + 0.4d2)]/(D2 - d2)
Where:
S = wall stress in psig;
P = minimum test pressure prescribed for water jacket test;
D = outside diameter in inches; and
d = inside diameter in inches.
S = PD/4tE
Where:
S = wall stress in psig;
P = minimum test pressure prescribed for water jacket test;
D = outside diameter in inches;
t = minimum wall thickness in inches;
E = 0.85 (provides 85 percent weld efficiency factor which must be applied in the circumferential weld area and heat affected zones which zone must extend a distance of 6 times wall thickness from center line of weld); and
E = 1.0 (for all other areas).
49 C.F.R. §178.51