I am ready to test my CPVC supply lines. Inspector wants 100psi (air) for test pressure. How long should the test last or hold that pressure to be safe and acceptable? Its been sitting for 2-3 hours and it dropped 10psi... possibly cuz' of the heat... Thanks.

Hi John:

In my area there is no stated time frame for testing water pipes. Just pressure, and in my area it is at 125 PSI.

My guess is that you will need to hold the test for no longer than 15 minutes without any drop in pressure. But never hurts to call the inspector and ask him. Each state seems to have their own requirements!

A ten pound drop sounds a little extreme to me... even with temperature fluctuations during a 2-3 hour time frame of a normal day... double check for leakers... even small ones with a bubble solution... check the test apparatus first... ;)

Let me know what you think...

MARK

I agree with Mark. I would expect the pressure to go up with the heat not down. You lost 10% and that's worth looking further. Even if you passed the inspection you'll have that leak anyway so look now.

In my region we test for 10 minutes. However, your drop is excessive. Look for a leak.

It was about 90 and humid when I filled it to 100psi, it was cooler when I noticed the drop. I let it sit over night so I'm going to check it today and see where its at. I'll check back with you guyslater when I get a look at it, thanks for the help.