02-08-2008, 09:19 PM
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Member
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Join Date: Mar 2007
Location: Ormond Beach, Florida
Posts: 8,238
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Re: A matter of code
Joshua,
On PEX jobs, in fact all plastic jobs, where I am doing code inspections, hydrostatic pressure is used.
In fact, even for copper the plumbers here apply hydrostatic pressure.
And, yes, even if the manufacturer says you can test plastic with air, the code says - " under a water pressure".
Also, don't forget to read that entire section ... the test must be "of not less than the working pressure of the system".
Unless "or, for piping systems other than plastic, by an air test of not less than 50 psi (345 kPa).", there is that "other than plastic" again.
If the PEX or CPVC system is going to be at 80 psi, then the test is at 80 psi. I had one in two towers I was inspection where I went up to inspect that section of the system and the plumber said 'No need to bother with the inspection, they pumped the system up and had a fitting blow off and spray water all over, that fitting was never glued on, in fact we checked all the fittings here and NONE were glued on.' Yep, an apprentice had done the work, measured everything, cut everything, marked everything so he could take it apart and align the marks when he glued it back together, but apparently had gone to lunch, come back and said 'oh, guess I did finish there'. Nope, he had not.
On a related note, what is the purpose of this code? Is it because the other plastic pipes, such as PVC, present an explosion hazard when filled with air?
Actually, it is the opposite, same with the increased pressure. 'They know' that 'other than plastic' piping is going to hold, that the piping itself is not going to crack, break, etc., and, using water instead of air, and at full pressure, will leave gushers (if you see them in time) and water all over if you miss the gushers. With air, if you are not there to hear it, once the pressure is gone, there is no evidence of the leak.
Of course, as a plumber, I am sure that you are well aware that cast iron DWV pipes are prone to cracks and pin hole leaks which only show up after that 5 foot of head (now 10 feet of head) is applied. - so it is not just 'plastic' but cast iron, of course, though, cast iron is not pressurized and plastic piping it.
Last edited by Jerry Peck : 02-08-2008 at 09:24 PM.
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