plumbing03.htm Essentials of Plumbing

Unit I: Legends,


Once the waste system rough-in is completed, test it for leaks. Repair any leaks found and retest the system. A water test and/or an air test can be used. Testing must be done before the walls are put up.

Using Plugs

Mechanical plugs. To test with mechanical plugs, place the rubber spreader into the opening to be plugged. Expand the rubber spreader by turning the wing nut and/or ratchet in a clockwise direction.

Mechanical plugs.


Inflatable air plugs. To test with inflatable air plugs, place the inflatable plug into the opening to be plugged. Inflate the plug with the hand-operated air pump.

Inflatable air plugs.


Performing a Water Test

A new system with oakum and lead joints must be filled with water at least 12 to 24 hours to allow the oakum in the joint to swell and form a water-tight seal. The system is then drained and tested. For all types of piping used in a waste system, use these steps to perform the test:

  1. Seal off all openings, except the highest vent opening, with plugs. Threaded piping can be sealed off with threaded plugs or caps.
  2. Fill the system with water through the highest vent opening and check for water leaks.
  3. If the water level drops more than 4 inches in 30 minutes, check the system for leaks.
  4. Remove the water from the system.
  5. Repair any leaks.
  6. Retest

Performing an Air Test

Use the following steps:

  1. With plugs, seal off all openings except one for the test equipment and gage.
  2. Force air through the system until the gage reads 5 pounds per square inch (psi).
  3. Let the air pressure remain at 5 psi for 15 minutes.
  4. Put a soapy solution on the joints to test for leaks.
  5. Release the air.
  6. Repair any leaks.
  7. Retest.

Most of the content of this course is provided courtesy of US Army Engineer School, Fort Leonard Wood, Missouri

Copyright David L Heiserman
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