Step 1: Turn off the Main Shutoff Valve
A good plumbing system in your home or building allows you to wash dishes, do the laundry, and shower effectively. However, if the water pressure is too high, it puts stress on your plumbing system as well as your appliances. And if it is too low, it makes it nearly impossible to create suds for washing dishes, to properly rinse off in the shower, or to even wash your hands.
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.
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.
For new systems, you may need to install the proper fittings to connect the 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, you can simply attach an adapter to a clean-out fitting and then install a tee.
For existing systems, attach the water gauge to either the laundry room faucet or an outdoor faucet that has a threaded spout.
Attach an adapter to a different faucet that allows you to connect the compressor hose. Next, attach the compressor to the faucet.
Turn on the compressor and allow the pipes to fill with air until the gauge reaches the desired test pressure reading. This test pressure reading is different for water systems and drain systems, so be sure toÿcheck the plumbing codes for the proper test pressure readingÿfor your system.
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 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.
Step 2: Install the Proper Fittings
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, and soldered joints.
Brass IPS joints, which are found in the water system, as long as they are not deteriorated, banged up, or destroyed, can usually be sealed by wrapping Teflon tape around the end of the threads of the pipe three times in a clockwise motion. Next, apply a thin layer of pipe thread sealant around the first three threads. Afterward, attach the pipe to the fitting using your hand and then a wrench until it fits just snug.
Step 3: Connect the Water Gauge
Compression joints work on a nut and ferrule system that, once the nut and the ferrule are attached, crush down on the pipe creating one pipe. Therefore, if it needs to be repaired, you?ll need to remove the damaged piece and then cut in another pipe to repair it.