How to Do Air Compressor Plumbing

An air distribution system for your shop can allow you to move that noisy compressor outside and clean up the tangle of hoses that seems to have taken up residence on the floor of your work area. The steps below are for black pipe. Both black pipe and copper have their advantages, and either will last for decades if installed correctly. Copper is more resistant to water damage, but more expensive and requires special skill to sweat joints correctly. Black pipe can last just as long if installed properly and is easier to put together without leaks.

Things You'll Need

• Tape measure
• Pipe and fittings
• Appropriate hangers for pipe
• 2 Pipe wrenches
• Pipe joint compound
• Torpedo level

Instructions

Preparation

1. Make a working plan of your shop. Place compressor in position and measure all plumbing from this point of origin.

2. Make a list of all fittings and distances between fittings. Most home improvement centers and plumbing supply stores will cut and thread black pipe to length for you, but you need to know the lengths in advance. A standard pipe length is 10 feet.

3. Plan shut-off valves and outlets. Assuming that your main distribution pipe will be attached to the ceiling of your shop, each outlet should be a vertical pipe running down the wall. At the bottom of each vertical outlet pipe should be a drain valve. The drain valve should be at least 6 inches below your working outlet.

Installation

1. Install a union at the compressor outlet. This will allow you to disconnect the compressor without disassembling a great deal of your plumbing if you need to repair or replace it. Use pipe compound on all threaded fittings. Pipe compound will help seal any small imperfections in threaded fittings.

2. Starting at the union on the compressor, assemble pipes and fittings. All horizontal pipes should be level and all vertical pipes should be plumb (check with level).

3. Install hangers at least every 5 feet on horizontal runs. For vertical runs, secure with hangers above and below outlets.

4. Pressurize and test system for leaks. Soapy water applied at all joints will help you discover any loose fittings.

Tips & Warnings

• The size of pipe you use should depend on the size of your shop. The average home shop will get good results by using a 1-inch main distribution pipe and 1/2 to 3/4-inch drop or working pipe.

• If you have more than one person working at a time in your shop or are planning a commercial system, there is an excellent formula for determining pipe size (see Resources section).

• Drain valves at the end of each vertical run will extend the life of the black pipe as well as your tools. The 6-inch space below an outlet will trap water and debris that would otherwise be forced through your tool or sit in the system.

• Open each drain valve at least once a day while using compressor.

• Compressed air can be very dangerous. Do not use PVC pipe as an easy substitute for black pipe or copper. When PVC pipe fails, it fails explosively. The shrapnel from this explosion can cause severe injuries.

References

• A workshop compressed air distribution system

Resources

• Compressed air systems: The secret is in the pipe