ASME B31.3: Process Piping Scope and Code Cases

Scope

This code 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 A 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.

Figure A: B31.3 Jurisdictional Limits and Options. (Source: ASME B31.3)

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 company 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.