Piping 1) B31.3 Process Piping 1-1) Why the piping spool is examined as per ASME B31.3? If the contract document states ASME B31.3 for the piping spool, it shall be applied. (If the purchaser is not familiar with B31.3 code, the piping spool should be tested and inspected as per B31.3 for the safety issue.) 1-2) B31.3 is not applicable for the following cases from (a) to (d) (a) piping systems designed for internal gage pressures at or above zero but less than 105 kPa (15 psi), provided the fluid handled is nonflammable, nontoxic, and not damaging to human tissues as defined in 300.2, and its design temperature is from −29°C (−20°F) through 186°C (366°F) (b) power boilers in accordance with BPV Code2 Section I and boiler external piping that is required to conform to B31.1 (c) tubes, tube headers, crossovers, and manifolds of fired heaters that are internal to the heater enclosure (d) pressure vessels, heat exchangers, pumps, compressors, and other fluid handling or processing equ...