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How to Safely Pressure Test Plumbing Systems

April 20, 2021 Viega
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In the fast-paced, high-demand world of piping, one of the most important steps of installing a system is to test it. In the interest of safety, we must ensure a system’s integrity before placing it into operation.

And while it’s part of every job, pressure testing should never be considered routine or an afterthought. Before pressure testing a system (hydrostatic or pneumatic), imagine the worst-case scenario and take the appropriate safety precautions to prevent it. For example, a large piping system being tested with nitrogen could endanger workers if it leaks and displaces oxygen in the air.

Compressed air or gases also can burst faulty connections, regardless of the joining method and turn them into flying shrapnel. The stored energy in 500' of 2" pipe at 150 psi is equal to eight ounces of TNT, more than enough to cause serious harm.

If working in an occupied building, make sure all workers are out of harm’s way. Warn any other tradespeople working in the area. Protect yourself as well. Contractors should always wear the appropriate personal protective equipment.

Hydrostatic testing is safer than pneumatic testing because water generates considerably less stored energy, but it’s not without risks. Murphy’s Law dictates that any rupture will empty into the computer server room and not into a stairwell. Also, hydrostatic testing isn’t always an option, especially in freezing conditions.

How to find unpressed fittings

Avoiding disasters like the above is why Viega invented Smart Connect technology. It makes it easy to detect unpressed fittings during pressure testing. Simply put, Viega press fittings will not hold pressure within a certain range if they are not pressed.

It eliminates the false positives that other fittings can yield, masking problems that will surface later. Smart Connect is built into every fitting for the ProPress system, MegaPress system, and PureFlow Polymer.

We recommend conducting initial pneumatic testing at ½ to 45 psi, monitoring the pressure test gauge, then walking the job to check for unpressed fittings. Our recommendation for initial hydrostatic testing is 15 to 85 psi, monitoring the pressure test gauge, followed by walking the job.

Final pressure testing should be done according to local codes. Once all fittings have been verified as pressed, you can test up to 200 psi pneumatic or 600 psi hydrostatic on metallic systems and up to 100 psi hydrostatic or pneumatic on PEX systems.

Options to make pressure testing easier

Testing a ProPress fitting system is easier with the Viega ProPress Test Plug. This simple device allows you to pressure test a system without making a press on the final fitting.

Simply insert the plug into the unpressed end of the final fitting and tighten by hand until it’s fully inserted. Then attach the test equipment to the included hose bib and perform the pressure test. Once it’s done you can drain the system through the hose bib and unscrew the test plug before making the final press on the system.

The test plug is available in ¾" and ½". Best of all, it’s reusable so it pays for itself quickly.

To learn more about the ProPress Test Plug, click here or watch this video. Learn more about Smart Connect here.

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