I've always air tested cpvc to 50# for an hour prior to hydro at the rough stage of installation, regardless of manufacturer's caution. Some dry fits can hold almost that much unglued when the pipe is properly supported and braced allowing little room for slipping. I hydro with premix glycerin in the winter and after 2 hours, drop it back to 100 and leave it for the sheet-rocking stage. And I advise them all it's under pressure so be careful screwing and most important (to me anyway) don't bend the head to meet your hole that's off just because you think you can. TD
Most CPVC manufacturers advise against air testing a CPVC piping system since pipe failures usually are very dangerous because of the plastic fragments produced by the pipe failure. There is a lot of energy store in a pipe system being tested with air. The stored energy is capable of causing a fatality due to flying pipe shards. I would recommend against testing with air. Regards Jim We have an AHJ requiring a 50 psi test on CPVC piping, we think that is excessive, and have always used 20 psi max. I know the best practice is to do a hydrostatic test, but thanks to the polar vortex we are having freezing temperatures and the builder needs to close up his walls. Right now we are looking for chapter and verse as to what the maximum recommended pressure is for an air test. Have looked through 3 different CPVC installation handbooks but the number is not jumping out at me. The TYCO Residential Dry System runs 10 - 15 psi pressure. Note: This is not a residential dry system we are trying to air test a system so the drywall can go on. When the building gets the heat turned on it will be a wet system. Richard L. Mote _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
