When plumbing is installed in new construction or during a remodel, local building codes may require an inspector to conduct a pressure check. To avoid paying high fees or failing the inspection, you can check the pressure in your pipeline prior to the inspector’s visit. Even if your pipe isn’t about to be checked, you can check the pressure to verify the quality of your installations, and identify and fix any problems before they become serious.
Prepare the system. It is preferable to check the water supply and drainage system (drain, waste and vent) when all pipes are installed, but before they are covered or inaccessible. The pipes must be dry and the main valve closed.
Block the drainage system. For a pressure measurement, you will need a system without air leaks. Block off the vent pipes and empty the tees near the main pipe. Seal all openings, such as drains and water intakes. You can do this by using sticky plugs or inflatable connecting plugs.
Connect the pressure pump and the gauge. Following the manufacturer’s instructions, connect the pressure pump and meter to an appropriate part of your drain system, such as a washing machine.
Put pressure on the plumbing system. Operate the air pump until the gauge registers five pounds (2.27 kg) per square inch (PSI).
Monitor the pressure. Check the pressure gauge constantly, for at least 15 minutes. If the pressure remains constant at five PSI, your drain system is safe and has passed the test. On the other hand, if the test fails, surely you must have a loss somewhere.
Check for losses. Even if the pressure remains constant during testing, you can still inspect your drain system for signs of small leaks, such as a soft hiss or air leak. If the pressure fails during the test, or if you suspect for any other reason that there is a leak, you can also check the joints by applying a small amount of soapy water and looking for bubbles from the air leak.
Repair losses. Once you’ve identified the source of a leak, you can fix the problem by reinstalling or replacing loose, faulty joints, or damaged parts of the pipes. You can then perform the pressure test again to verify that the problem has been resolved or find out what repair needs to be done.
Test the water supply lines. Generally, you can pressure test your supply lines simply by opening the water outlet and checking the entire length of the system for any leaks that the water pressure reveals. However, if you prefer an air pressure test, you can follow the same steps as with the drain system.
Tips
You can buy the necessary equipment and tools at a hardware store or plumbing store, you can also rent the equipment for less cost at a rental business. Check your local building codes, or call a licensed inspector to find out if a pressure test is necessary, and to find out about any specific requirements, such as pressure and time testing.
Warnings
When conducting an air pressure test, wear safety glasses and other protective equipment. Be extremely careful, especially when checking gaskets and seals. High pressure could cause the joints to come loose at high speed, or create other potential hazards.
