Recently (3 weeks ago) posted on a potential leak in water line in kitchen behind cabinets. Found leak w/o removing cabinets – only opened the back wall of base cabinet & lucked into leak location. 1/8 inch drilled hole in HW line. Fixed it w/ a lot of cussing, replacement CPVC, fittings & glue. Pressure testing it w/ air. County wanted 100 psi for 24hrs when we had inspection. It passed then – about a yr ago.
Question: I just looked at it in a few minutes ago (24 hrs ended about an hour ago), and it lost about 20 psi since 8:00 last night. It had lost nothing discernable to that point – about 11 hrs. I have overcome the urge to rend my clothing, gnash my teeth and tear out my hair. I chose to just cry softly while curled up in a fetal position in a dark corner. Is it time to turn on the water and look for drips? Have tested all new joints & threaded joints w/ shampoo, looking for bubbles. Nothing, zip, nada, nichts, zilch.
Don
Edited 7/29/2003 11:25:25 AM ET by Don
Replies
Don, don't know how much it will help, but when doing my gas line (we have a 15 lb test for 10 or 20 minutes here) I found a leak (well, I knew there was a leak beforehand as I am coming in after my plumber). I had to wrestle with some 1 1/2" galv pipe. When I was in a plumbing supplier to get a left/right hand thread nipple and some other stuff, I discussed this pressure testing thing with the guy at the counter. He remarked that in an overnight setting the pressure can fluctuate due to temps. And I gotta imagine with your use of CPVC for your water lines, there could even be more variance with the pressure overnight.
First thing I would do it pump up the lines again and see what happens in a couple/few hours.
BTW, our water test is just the pressure that comes off the street.
Don, I feel your pain!
Remember your first test? Did you have fixtures and valves in place?
Most fixture valves are designed to operate between 60 and 80 psi. They may be bleeding off the excess pressure. Even if they were in place for the first test, they are a year older now, and have a little wear on them.
Could also be as Wiley suggested; temperature differences over night.
FWIW, 100 psi street pressure unregulated into hot water heaters around here caused many tank failures. Plumbing supply houses were going nuts trying to figure out why so many HWH in this county were failing. It was the high incoming water pressure. Reducing the pressure to 65 psi with pressure regulators solve the county wide problem.
Dave
Actually Dave, I don't even know what our pressure is coming off the street; but I probably failed to point out that I believe, in new construction, we are required to have a pressure regulator--I haven't come to that point in my construction yet, but I think I remember something along those lines (I would have to go back and look at my plans in some notes I had to address before final approval for my permit).
Don,
the 100psi test is for new construction w/ NO FITTINGS. all lines/nipples are to be permenantly capped. and no WH either.
now that you have all fittings and the WH installed, 50psi is required. your system has passed the test in my opinion. I am hoping that you have not damaged anything by appling 100psi. See Daves post.
leave the pressure guage in place, drain the air and charge with water at line pressure, wait 1 hour before recording the psi and recheck at the same time of day 24 hours later. See Wiley's post. Oh yeah close the feed valve after recharging system.
SamT
"Law reflects, but in no sense determines the moral worth of a society.... The better the society, the less law there will be. In Heaven, there will be no law, and the lion will lie down with the lamb.... The worse the society, the more law there will be. In Hell, there will be nothing but law, and due process will be meticulously observed."
Grant Gilmore, The Ages of American Law (New Haven: Yale University Press, 1977), pp. 110-111.
From 32866.117
Sam: Among you, Dave & Wiley, I think I have my answer. Pressure stabilized at 80 psi. It is still there tonight, nearly 36 hrs after charging. Original test, one yr ago was, indeed, w/o valves, except for the washing machine double hot - cold valve. HWH was in systen, but it is an electric demand heater, so no tank. This test has all valves in system, all are 1/4 turn ball valves, and all are turned off. Temp here in Nawth Jawja got to over 95 in Sun yesterday, and dropped to about 70 in the nearly New Moon last night. AC is functioning and house is super insulated. I checked pressure several times yesterday, and it stayed at 100. Was at 80 at about 10:00 this AM. Did not go up during today; stayed right on 80. Day was just as hot as yesterday. System is broken open at HWH so I can check both systems independently. I know I have some small leaks in cold side, most likely at threaded connections. Took 4 tries to get union at washer location sealed. Have at least one more slow leak in cold side. At a valve, have seen bubbles in shampoo when I checked it. I have a well system, and do not know what pressure it operates at. Will check, but am sure it is NOT 100!
Thanks, guys for all the help.
DonThe GlassMasterworks - If it scratches, I etch it!