Power Pipe vs. Process Pipe

• Power Piping as per ASME code B31.1:

The B31.1 code prescribes minimum requirements for the design, materials,fabrication, erection, test, inspection, operation, and maintenance of piping systems typically found in:

- Electric power generating stations,

- Industrial institutional plants,

- Geothermal heating systems, and

- Central and district heating and cooling systems.

The code also covers boiler external piping for power boilers and high temperature, high pressure water boilers in which steam or vapor is generated at a pressure of more than 15 psig; and high temperature water is generated at pressures exceeding 160 psig and/or temperatures exceeding 250 degrees F.

• Process Piping as per ASME code B31.3:

This code prescribes requirements for materials and components, design, fabrication, assembly, erection, examination, inspection, and testing of piping. The B31.3 Code contains requirements for piping typically found in:

- Petroleum refineries;

- Chemical, pharmaceutical, textile, paper, semiconductor, and cryogenic plants; and

- Related processing plants and terminals.

This Code applies to piping for all fluids including:

(1) raw, intermediate, and finished chemicals;

(2) petroleum products;

(3) gas, steam, air and water;

(4) fluidized solids;

(5) refrigerants; and

(6) cryogenic fluids.

Also included is piping which interconnects pieces or stages within a packaged equipment assembly.

So, ASME B31.3 includes :

1. All piping within the property limits of facilities engaged in the processing or handling of chemicals or petroleum or related products.

And ASME B31.3 excludes :

1. Non-hazardous fluid Piping with pressures between 0 and 15 psi (100 kpa) and temperatures ranging from - 20 ^oF (- 29 ^oC) to 366 ^oF (180 ^oC ).

2. Piping covered by ASME & PV Code, Section I and or B31.1, which requires SectionaI inspection and stamping.

3. Pressure vessels, heat exchangers, pumps, etc., including internal piping and connections for external piping.

4. Piping within the property limits which has been designed for design according to B31.4 or B31.8 or to government regulation (Pipeline rights-of-way).

5. Plumping or sewers.

6. Piping for fire protection systems covered by insurance underwriter's requirements.