How to get the water out of air compressor lines

Written by meg jernigan
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How to get the water out of air compressor lines
Campbell Housefeld air compressor (Campbell Housefeld, TP Tools & Equipment)

One of the components of air is water vapour, which we usually think of as humidity. When a compressor pressurises the air by reducing its volume, most of the water vapour condenses into liquid water and remains in the compressor tank and air lines. This moisture can damage pneumatic devices and rust compressor piping. Adding a water separator to the compressor lines will eliminate the water and extend the life of your air tools. Follow a few simple steps to remove the water from air compressor lines with a water separator.

Skill level:

Things you need

  • Water separator
  • Wrench
  • Teflon tape
  • 1/2-inch pipe nipple

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  1. 1

    Purchase a water separator with a higher CFM (cubic feet per minute) and PSI (pounds per square inch) rating than the tools you use with your compressor. These ratings are usually stamped onto air tools and can be found in the tools' product literature.

    How to get the water out of air compressor lines
    TP Tools & Equipment water separator.
  2. 2

    Unplug the air compressor or turn off its power at the circuit breaker. Empty the tank completely by opening the drain plug on the bottom.

  3. 3

    Locate the output pressure regulator on your compressor. Use a wrench to remove the regulator from the pipe fitting that connects it to the compressor.

  4. 4

    Wrap Teflon tape around the pipe fitting threads and screw on the "in" side of the water separator, hand tight plus 1 1/4 turns. Connect a 1/2-inch brass or iron pipe nipple to the "out" side in the same manner.

    How to get the water out of air compressor lines
    Brass pipe nipple.
  5. 5

    Tape the threads on the other side of the pipe nipple, and screw on the regulator, hand tight plus 1 1/4 turns. Close the drain valve and restore power to the compressor.

  6. 6

    Check the water level, and empty the separator as directed by manufacturer.

Tips and warnings

  • Drain water from the air compressor's tank frequently through the drain valve.

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