What is process piping and power piping?

Industrial facilities, such as factories, power plants, and refineries, rely on process and power piping to safely transport fluids. However, the two types of piping are not the same. They have very different purposes. 

In this post, we explain what each is in turn and then compare them to each other, highlighting the critical differences between the two. 

What Is Process Piping?

Process piping is a system used to transport liquids, gasses and chemicals around an industrial facility. It is currently the safest and most effective way to do this. 

From the outside, process piping can look like regular plumbing. However, it is not the same. Engineers design the piping according to the specific fluids it needs to transport. 

Process piping is found in a variety of industrial settings, including water treatment facilities, breweries, pet food processing plants, petrochemical plants, pharmaceutical manufacturing facilities and food factories. All of these plants need systems that let them quickly, affordably, and reliably transport fluids from one location to another. Process piping includes multiple accessories, such as rubber hoses, gaskets, flangers, traps, filters and strainers to enhance the quality of the end product and improve reliability. 

Both process piping and plumbing must adhere to various regulations. However, the standards for each are different. Plumbing needs to follow building codes for transporting water and removing sewage. Therefore, pipes are usually made of copper or plastic. On the other hand, process piping must adhere to the regulations that apply to the particular process manufacturers are using it for. Codes for food transportation are different from those for chemical transportation. Processing piping must also follow OSHA standards for safe operation. 

Process piping can be made of a wide variety of different materials, both metallic and non-metallic. Common metallic options include carbon steel, austenitic stainless steels, and nickel-based alloys or titanium for more corrosive applications. Non-metallic materials include glass-lined metallic piping, borosilicate glass piping (in some pharmaceutical applications), fiberglass, and reinforced thermosetting resin materials. Applications may also require thermoplastic piping, an affordable solution with high corrosion resistance against aggressive compounds. 

What Is Power Piping?

Power piping refers to piping systems that transport water or air at high temperatures or pressures. Usually, builders install this type of piping in conventional and geothermal power plants and in facilities that require heating and cooling systems for large areas. Pipes can contain hot water, compressed air, or liquid formed by condensation. 

More generally, power piping systems and their component parts are not building services piping systems. 

Again, power piping is not a part of regular plumbing. Pipes must be able to withstand temperatures and pressures to the levels set out by the building specification, not general plumbing codes. They are made of materials specifically engineered to withstand intense applications. 

What Is The Difference Between Process Piping And Power Piping?

As the above discussion indicates, there are substantive differences between process and power piping. Process piping is a method of delivering liquids, gasses, and other chemicals to parts of the manufacturing plant, typically for mixing products. It relies on both pipes and ancillary components, and may both transport and minorly process fluids before they reach their intended destination. 

Power piping, by contrast, is usually installed in central heating and cooling systems for large areas, or power plants. Piping is designed to withstand the high pressures and temperatures associated with boilers, as well as compressed air and high-temperature condensation. 

ASME B31.1 rules govern power piping while ASME B31.3 rules govern process piping. These rules set out the specifications and tolerances of each type of piping, depending on the application. 

For instance, designers build power piping for the following applications:

  • Boiler steam pressures greater than fifteen pound per square inch gauge
  • High temperature water generating pressures of more than 160 pound per square inch gauge
  • High-pressure and high-temperature water condensate in excess of 250 degrees F
  • High temperature water piping from high pressure district boilers

By contrast, process piping focuses more on the chemical or fluid being transported. According to the ASMA B31.3, plants using process piping must adhere to component, design, assemble, erection, examination, inspection and testing rules. Process pipes should be suitable for the transport of: 

  • Refrigerants
  • Cryogenic fluids
  • Petroleum products
  • Raw and intermediate chemicals
  • Fluidized solids


Process piping and power piping differ from each other and from regular plumbing. Builders must construct each to the specifications of the task at hand, as well as American Society of Mechanical Engineers’ guidelines.