For the purpose of the Washington state public works law, chapter 39.12 RCW, plumbers, pipefitters and steamfitters assemble, install, and maintain piping systems, fixtures and equipment for the transportation of water, steam, gas, air, sewage, oil, fuels, liquids, gases, or similar substances.

The work includes, but is not limited to:

(1) Piping systems installed in structures (e.g., buildings, industrial plants, etc.).

(a) The handling and moving of any plumbing, pipefitting and steamfitting materials, supplies, and equipment on the job site.

(b) Cutting, threading, and bending pipe.

(c) Joining pipes by use of screws, bolts, fittings, solder, welding and caulking, or any other method of making joints in the pipefitting industry.

(d) Assembling, installing, and repairing valves, pipe fittings, and pumps.

(e) Testing the piping system.

(f) Installing and repairing plumbing fixtures, such as sinks, bathtubs, water heaters, and water softeners.

(g) Cutting holes in floors and walls for pipes:

• With point and hammer.

• Core-drilled.

(h) Responsible for all cleanup required in connection with plumbers, pipefitters and steamfitters work.

(2) Distribution lines (e.g., water mains, sewer mains, oil and gas lines, etc.).

(a) The handling and moving of any plumbing, pipefitting and steamfitting materials, supplies, and equipment on the job site.

(b) Steel pipe: Welding of pipe joints and joining pipes with screws, bolts, fittings, solder, caulking, or any other method for making joints in the industry.

(c) Ductile iron pipe: Joining pipes by using any method for making joints in the industry, when the pipe will be under pressure.

Assembling, installing, and repairing valves and pumps.

(d) Testing the piping system.

(e) Responsible for all cleanup required in connection with plumbers, pipefitters and steamfitters work.