ASME B31.3 code for process piping prescribes requirements for the materials, design, fabrication, assembly, erection, examination, inspection, and testing of piping within the property limits of facilities engaged in the processing or handling of chemical petroleum or related products. Figure A4.4
provides an illustration of the scope of ASME B31.3. The requirements of ASME B31.3 apply to piping for all fluids, including raw, intermediate, and finished chemicals; petroleum products, gas, steam, air, and water; fluidized solids; and refrigerants.
In case of packaged equipment, the interconnecting piping with the exception of refrigeration piping shall be in compliance with the requirements of ASME B31.3. The refrigeration piping may conform to either ASME B31.3 or ASME B31.5.
The requirements of ASME B31.3 do not apply to piping systems designed for internal gauge pressures at or above 0 but less than 15 (100 kPa gauge) psig provided the fluid handled is nonflammable, nontoxic, and not damaging to human tissue
and its design temperature is from —29°C (—20°F) through 180°C (366°F).
The following piping and equipment are not required to comply with the requirements of ASME B31.3:
Power boiler and the boiler external piping
Piping covered by ASME B31.4, B31.8, or B31.11, although located on the com- pany property
Piping covered by applicable governmental regulations
Piping for fire-protection systems
Plumbing, sanitary sewers, and storm sewers
Tubes, tube headers, crossovers, and manifolds of fired heaters which are internal to the heater enclosures
Pressure vessels, heat exchangers, pumps, compressors, and other fluid-handling or processing equipment, including internal piping and connections for external piping
Effective Edition, Addenda, and Code Cases
The effective edition, addenda, and code cases shall be determined similarly to the approach delineated for ASME B31.1 for piping systems other than the nuclear safety-related piping systems. #Little_PEng
