This is an example for ASTM A106 specification, refer from ASTM A530 Specification.
Other material you may refer in specified standard.
Each length of pipe shall be tested not less that 60% of the minimum specified yield strength for carbon and ferritic alloy steel pipe, or 50% of the specified minimum yield strength for austenitic alloy steel pipe.
Equation: P = 2St/D or S = PD/2t ,
- P = hydrostatic test pressure (psi or MPa),
- S = pipe wall stress (refer to ASME II Part B) ,
- t = wall thickness, nominal wall, D = outside diameter.
NOTE: hydrotest values are essential identification by marking on pipe.