An air compressor is a valuable component of many workshops, whether the air is used to drive pneumatic tools, spray paint or simply inflate tires. Distributing the compressed air through piping to the work areas is almost essential in a large shop, and even in a small shop it helps avoid a tangle of air hoses. For nearly a century, the industry standard for compressed air piping has been black iron pipe (BIP), a high strength, rust-resistant, threaded steel tubing that's relatively inexpensive. This guideline will explain how to install BIP air compressor piping in your workshop.
Measure the route where you will install the piping and read the suggestions below to determine how much pre-threaded BIP and how many fittings you'll need.
Pencil or chalk a line along the wall or other surface where the pipe will run. Allow for a 0.5-inch drop per 10 feet of length from the highest point to the end.
Join BIP sections with iron pipe couplings. Wrap Teflon tape around the male threads of each pipe and hand-tighten the coupling onto the pipes. Use elbow fittings for joints in corners and tee fittings for pipe drops and extensions. Tighten the connection an extra 1.5 turns with a pipe wrench.
Secure the piping to the wall with steel pipe straps spaced 4 feet apart. Use 1.5-inch wood or masonry screws to hold the clamps in place.
Install tee fittings in the piping at each work station, with an air line fitting in the open end of the tee. Wrap the air line fitting threads with Teflon tape and tighten them in the same manner as the other pipe fittings.
End the piping with an elbow and a short vertical length of pipe to serve as a line drain. Terminate the pipe with an air line fitting or a valve that can be opened to drain accumulated moisture in the line.
Pre-threaded BIP is available in lengths from 6 inches to 21 feet. One-half-inch Schedule 40 BIP is rated at 236 psi (250 psig) for gas and is practical for most applications. Install an inline water separator between the compressor and the first work station. This will remove most of the water and compressor oil from the compressed air and keep the air in the line dry.