Having trouble converting 13" water column to standard psi preasure? Relocated propane tank and running all new service line's and wanted to test piping before coverage. Not knowing what the the proper psi test should be? Thanks
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Preasure test for gas service
- Thread starter Sturgeon
- Start date
larry4406
Well-known member
We test all our gas piping at 15 psi.
Use a small range gage (0-30 psi) and have a Schrader valve with cap on it.
Our inspectors arrive, note the pressure, drop it to around 8-11 to see the needle move, do other inspections, and check it last.
We keep our test on for 24 hours prior to inspection, not sure what Code requires.
Use a small range gage (0-30 psi) and have a Schrader valve with cap on it.
Our inspectors arrive, note the pressure, drop it to around 8-11 to see the needle move, do other inspections, and check it last.
We keep our test on for 24 hours prior to inspection, not sure what Code requires.
rlitman
Well-known member
13" water column is under 1/2 PSI. Your best option is to make your manometer using some clear tubing, a 2x4, some romex staples, some water tinted with food coloring and a ruler.
LeeG
Well-known member
27" of water is 1 psi. The last time I did a natural gas line, we put I think 5 or 7 psi in and made sure it held for 10 minutes or so. Each state should have the test requirements published.
engineer2
Well-known member
13 inH2O = 0.4696 psi. A digital gauge will let you see a pressure drop more easily, but they are not common in such low ranges.
Soap bubbles will work just as well.
Soap bubbles will work just as well.
just don't have your appliances hooked up when doing pressure test . it's way too high for them.
larry4406
Well-known member
Here the plumbers close the isolation valve at each fixture and test against the closed valve. Once metered, they test the fittings downstream of the valves (that weren't pressure tested) using soapy water.just don't have your appliances hooked up when doing pressure test . it's way too high for them.
micromind
Well-known member
A true pressure test would be to pump it up until something blows, fix it then use a bit less pressure and see if it holds.........lol.
Around here for natural gas or propane, the inspector will want to see 10 - 15 PSI, valves can be installed and closed or lines capped off. If the pressure is the same after the inspection, it's good.
Around here for natural gas or propane, the inspector will want to see 10 - 15 PSI, valves can be installed and closed or lines capped off. If the pressure is the same after the inspection, it's good.
Firebrick43
Well-known member
A proper pressure test for an LP system has the appliances hooked up and valves to the appliances on but pilots off. Otherwise you don't know if the appliances are leaking as well
A manometer is the cheap way, you can make one as RLitman described or buy a cheap one. Gauges sensitive enough are more expensive and while handy, not as sure fire accurate as a manometer.
The tank is turned on to pressurize the system at 10.5" of WC. 13 is to high and the regulator needs adjusted down.
The tank service valve is then shut and gas is slowly bleed off the system till its 9" of WC. If you don't do this step you will not unlock both regulators. Then the possibility exist that the 1st stage regulator could make up for the loss of gas of a tiny leak and you will not see it.
After you lower to 9" WC and there is no hysteresis, The pressure level can not drop during the duration of the test. NFPA 58 test length is 3 min but we do 4 min. A very tiny leak will be noticeable with a manometer.
A manometer is the cheap way, you can make one as RLitman described or buy a cheap one. Gauges sensitive enough are more expensive and while handy, not as sure fire accurate as a manometer.
The tank is turned on to pressurize the system at 10.5" of WC. 13 is to high and the regulator needs adjusted down.
The tank service valve is then shut and gas is slowly bleed off the system till its 9" of WC. If you don't do this step you will not unlock both regulators. Then the possibility exist that the 1st stage regulator could make up for the loss of gas of a tiny leak and you will not see it.
After you lower to 9" WC and there is no hysteresis, The pressure level can not drop during the duration of the test. NFPA 58 test length is 3 min but we do 4 min. A very tiny leak will be noticeable with a manometer.
fitter30
Well-known member
There is very little volume in most systems. With all equipment valved off 30 minutes is more that enough time to see the gauge drop. If piping is outside ( more than couple of feet) and the sun is going in and out of clouds pressure will change from full sun to behind.
larry4406
Well-known member
Ambient temperature can affect pressure tests on black pipe. Personally I like a 24 hour test.
YMMV.
YMMV.
The city I worked in wanted a 25 PSI test. No regulators in the system and no appliances connected.
Once that passes then put in any regulators, connect the equipment and gas supply and bubble test any disturbed connections.
Firebrick, our inspector would have an aneurism if we did the initial test with the supply gas!
Once that passes then put in any regulators, connect the equipment and gas supply and bubble test any disturbed connections.
Firebrick, our inspector would have an aneurism if we did the initial test with the supply gas!
Jim greengo
Well-known member
You can get a screw on pressure test gauge at a box store.
If you don't see a leak in a few minutes with a 15 or 25 PSI test it probably isn't leaking.Ambient temperature can affect pressure tests on black pipe. Personally I like a 24 hour test.
YMMV.
We would buy 50 PSI 3" diameter test gauges and a very tiny leak would show up right away in most systems. We would watch the test gauge for 15 minutes. A leak that would blow a pin head bubble with soapy water, once every 30 seconds would show up on the gauge.