How to Use a Plumbing Pressure Test Kit

Why do you need to use a plumbing pressure test kit? There are situations where the water pressure of a plumbing of a pool or other plumbing apparatus is in question. A hydrostatic pressure test also known as a plumbing pressure test kit is performed on a home or building’s sanitary sewer system to determine if there are water leaks present in the plumbing system. An inflatable test ball is inserted into the building or home mainline sewer clean out and is then inflated in order to block or plug the main sewer line.Well, regardless of the suspected location of the problem, a pressure test of all plumbing lines should be done to confirm whether the leak is in the plumbing or the structure (shell) of the pool. Using the process of elimination, pressure testing allows you to conclusively isolate which part of the pool is leaking so later location procedures can be efficiently targeted.

Test Your Plumbing System

Testing your plumbing system with air allows you to assess the condition of your plumbing system without water. It is especially useful in cases where there is no water available on the site, the building is unheated, which can cause the pipes to freeze, or when water leaks can cause damage. However, because compressed gas can cause the pipes to explode under extreme pressure, which can cause personal injury, and in some cases even death, it is especially not recommended for plastic piping or for individuals without extensive knowledge and skills in testing plumbing systems with air.

Fill Plumbing Pipes with Pressurized Air

Filling plumbing pipes with pressurized air is a quick and effective way to inspect for leaks in new installation of water pipes and drain/waste/vent systems. You can also air pressure test existing pipes, however, pumping the drain/waste/vent system full of pressurized air becomes impractical after installation of the plumbing fixtures and connection to the sewer.

How to Pressure Test Plumbing with Air

Step 1: Turn off the Main Shutoff Valve

If you are testing an existing water pipe system, you first need to turn off the main shutoff valve. Afterward, allow the water to drain from the pipes. Once the all of the water has been drained, shut off the faucets.

For a new system, place a cap on all the stub-outs connected to the system you are assessing. For water systems, solder or glue the caps to test the pipes in your system.
As for drain vent waste systems, you can simply glue a cap to all the stub-outs with plastic pipe cement. Once the testing is complete, cut the caps off.

Step 2: Install the Proper Fittings

For new plumbing systems, you may need to install the proper fittings to connect the air pressure gauge and the air compressor hose to the system.

As for water systems, this can be done simply by leaving the cap off of one of the stub-outs. Afterward, install a tee and an adapter for the compressor hose and the pressure gauge on that stub-out. For waste systems, all you need to do is to attach an adapter to a clean-out fitting and then install a plumbing tee.

Step 3: Connect the Water Gauge

For existing plumbing systems, attach the water gauge to either the laundry room faucet or an outdoor faucet that has a threaded spout.

Step 4: Connect the Compressor Hose

Attach an adapter for the compressor to a different faucet that allows you to connect the air compressor hose. Next, attach the air compressor to the faucet that you plan to test.

Step 5: Charge the System

Turn on the air compressor and allow the plumbing pipes to fill with air until the pressure gauge reaches the desired test pressure reading. This test pressure reading is different for water systems and drain systems, so be sure to check the plumbing codes for the proper test pressure reading for your system.

Step 6: Turn off the Compressor

Shut off the compressor and allow the system to pressurize for 15 minutes. At this point, you may remove the compressor hose and leave the pressure gauge in place. It is not uncommon to hear air escaping the pipes if there are leaks present in the system.

If after some time the pressure gauge reading remains the same, then there are no leaks present in the system. However, if the gauge goes down, it indicates a leak in the system.

Step 7: Repairing Plumbing Leaks

If after trying the seven steps how to pressure test plumbing with air, it reveals leaks in your plumbing system, you can simply contact a professional plumber and have the system inspected and repaired. Alternatively, if you feel confident, you can try to repair the leaks yourself.

Most commonly leaks in a plumbing system occur in the joints, meaning any connections between pipes. There are basically three types of joints:

  • IPS joints
  • Compression joints
  • Soldered joints

If Your Water Pressure is Low

If you find that your water pressure is very low (below 30 pounds per square inch), there is a good chance that you have a leak somewhere in your plumbing. Or this indication of low water pressure could be due to some sort of debris build-up that’s prohibiting an efficient flow of water through the plumbing.

A Future Plumbing Pressure Tip

So, the next time you’re wondering how to pressure test water pipes, try the above plumbing pressure test to quickly assess your home’s indoor plumbing. It’s a quick, easy and effective way for you to assess the health of your home’s plumbing.