Inspector wants me to pressure test my copper piping for the new tankless water heater before putting water into the system. Sounds reasonable to me. He did give me permission to tie into the existing water system (this is a remodel), just use a shutoff and keep it off until he signs offf (same with gas, but I’m not doing that part).
Question – what PSI do I put on copper piping? 10, 50, 100? I forgot to ask while I had him on the phone and won’t have time to get him tomorrow.
Thanks -MERC
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10 lbs works when I call my inspections in . If it wont hold 10 it sure wont hold 100!
They do get upset if we stick the wrong size gauge on the test. 0-30 psi is good, 0-100 psi is bad!
I guess I should have figured 10 would be good since that is what the gas company does. I'd expect if it holds 10 psi of air, it will hold significantly higher in water.
As a side note (rant), I went to Lowe's and HD to see if they had the gauge and schrader valve fitting. "Ummm....yeah, I know exactly what you are talking about...but we don't carry it". To which I respond to both of them "You know you carry 80% of what I need to build a house". Idiots.
Thanks MERC
Call the inspector and ask.
Here, we are required to use water line pressure for the test. 60 lbs, for 24 hrs.
If you test to low and he comes back, you won't be able to convince him it did not leak down.
Dave
Are you testing the water line or the gas line?
I do not think 10 lbs is nearly enough for water.
Gas company has already done the gas line and it is sitting at 10psi rock solid.
I need to do the water lines. I am going to the Plumbing supply house here, they will know what I need. If they don't, I'll just crank it way up, 80 lbs or something. Maybe I should go for 200 psi and see if the inspector runs out of the house....just kidding....
But seriously, my inspectors are pretty reasonable around here and as long as I do something reasonable they will be ok with it.
MERC.
A copper water system would generally be good for more than the 200psi. Of course, it would only see those pressures (and higher) in a freezing event, or a freak event involving the water heater.
The burst pressure for hard Type M 3/4 inch copper is 2600psi, though the rated working pressure is about 700psi. A Tin/Lead solder joint is rated for 'just' 200PSI (@100F), though the Tin/Antimony stuff is good for 1090psi(@100F).
See: http://www.copper.org/applications/plumbing/techref/cth/cth_3design_burst.htm
Edited 10/22/2004 11:10 am ET by csnow
Very cool. Thanks
I just got back from the plumbing supply and I got a couple of 200 psi gauges and a "gas test block". The guy said he would put it at 100 psi or so, give or take. I'm going to thread one such assembly onto each of my supply nipples on one of my sinks.
MERC
>>Tin/Lead solder joint is rated for 'just' 200PSI
This might be a dumb question because it's waaay out of my area, but -- is lead solder approved for drinking water systems?
This might be a dumb question because it's waaay out of my area, but -- is lead solder approved for drinking water systems?
No, I believe it was banned around 1987, but the poster's system may still have old sections with lead solder. Not that it should be tested at 200psi, of course...
Gas is tested to a low pressure because the gas pressure in a house is very small, less than one psi. Water will normally run 40 to 60 psi. I'd test it to 80 or 90 or so. Then you'd be certain you have a completely leak free system.
Go with 100. Not 99, 97 or 102. Pressure it up. Wait the required time (24 hrs?) and check gauge. If not exactly at 100. Problemos. You could use a product known as Snoop to check joints after pressured up. Pretty much a commercial soap and water mix--but better. Gas and H2O have different molecule sizes. H2O molecules bigger. Remember Gortex? Keeps water out but lets vapor (gas) escape. Tyr
The only reason I said 80 or 90 is that many air compressors don't go to 100. But 100 is fine. There's no way you'll blow up copper pipe at that pressure.
No, but if there is a pressure balancing shower valve in the rough in system, it could damage it. Around here inspectors want the pressure balancing tube/shower valves installed at the rough in inspection. Best to test it at whatever the operating pressure will be.
Dave
The 2000 IRC calls out" Test under working pressure or 50psi for 15 mins. We still use the 97 UBC on my job site. WE have had problems with 50 psi (mostly people opening valves.) We call all roughs at the same time 60+ mins for 1 address , so if we hold the 10 psi for the inspection it is ok @ 10 with my inspectors.
Gas pipe they let us go 10 psi also, I think the IRC is 3 psi for 15 mins.Plastic for ground plumbing they let us go with 5 psi which is also what most codes call for or fill with water & a 10' Head. They also make us fill the DWV with water to the truss line on rough inspections, during the winter months they let us slide if it is real cold!
So I pumped up yesterday to 100 psi (my house water pressure is 90 psi). One gauge has fallen to 95 psi and the other to 85 psi (overnight). Does this sound "normal". The gauges would have fallen to ambient temperature last night (50 or so), so that might have something to do with it. The gauge on my gas line has fallen from 10 psi to 9 psi in about 3 days and I know there are no leaks in that.
I'm hoping my shutoff valves are slightly leaky. I haven't plumbed the other side of the shutoffs into the existing water system yet, so if they leak air it will just go into atmosphere (as opposed to having water pressure on the other side of them).
MERC.