Pressure Test Propane System

Started by walker, October 28, 2017, 07:31:03 PM

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walker

I need to do a pressure test tag for a propane system, never done one on a propane system before.  Obviously I can't do a soap and dial test.  Would I disconnect at the tank and pressurize from there 15 PSIG for 15 mins with the pipes capped at the shut off? most the shut-offs are only rated for 1/2PSI, so can't pressurize at 15PSIG.   Its for a residential water heater and furnace.

Admin

Yes, most people don't realize the specs on most shut off valves allow far less than 15PSI.  A TSSA inspector told me the shut off valve should be removed and line capped before pressure testing.  Then after you reassemble the piping system and turn on the tank use soap or a manometer to test.

walker

I think the codebook talks about a manometer test when there is no gas meter involved.

I'm going to investigate that, I really never work on propane so I'm not very familiar with pressure testing a propane system.


Admin

Quote6.22.2  Before appliances are connected to a new piping and tubing system containing fittings or joints, a   pressure test shall be applied using either air or an inert gas (e.g. nitrogen) in the following manner:
(a)  Appliance shut-off valves, meters, regulators and any component not rated for the test pressure being applied shall not be connected to the piping or tubing system under test.
(b)  The test pressure shall be measured by either a pressure gauge or equivalent device and, if a gauge is used, the minimum diameter shall be 3 in (75 mm) and the maximum range shall exceed the test pressure by at least 15% but not more than 300%. The pressure gauge or equivalent device shall be calibrated to read in increments of not more than either 2 psig (14 kPa) or 2% of the maximum dial reading of the pressure gauge, whichever is less.
(c)  A pressure recorder when used for this test shall have a maximum range and be calibrated to the requirements of sub-section (b).
(d)  The pressure and duration of the test shall be in accordance with Table 6.3.

6.22.3  After an appliance(s) is connected, the new system shall be tested in the following manner:
(a)  Before turning on the gas for the test, a check shall be made to ensure that any opening from which gas can escape is closed;
(b)  Immediately after allowing the gas into the piping or tubing system, a test shall be made to determine that no gas is escaping by carefully watching the lowest volume test dial of the meter, or by using a pressure gauge or manometer (fluid, mechanical, or electronic) as specified in 6.22.3 (c);
(c)  Where a meter is not provided, a working pressure isolated system (supply shut off) test shall be completed and the pressure shall be measured with either a pressure gauge or equivalent device calibrated to read in increments not greater than those specified in Clause 6.22.2(b), with the following exceptions: (i)  for a system where the working pressure is 0.5 psig (3.5 kPa) or less, the pressure gauge or equivalent  device (e.g. a manometer) shall be calibrated to read in increments of not greater than 1 in w.c. (250 Pa); and (ii) for a system where the working pressure exceeds 0.5 psig (3.5 kPa) but does not exceed 5 psig (35 kPa), the pressure gauge or equivalent device shall be calibrated to read in increments of not greater than 2 in w.c. of pressure (0.5 kPa); and (iii) For this test the gas supply shall be shut off and the contained gas pressure shall be monitored for leakage indicated by a pressure drop.
(d)  The test described in subsections (b) and (c) shall be of a 10 minute duration; (e)  Each appliance connection, valve, valve train, and system component shall be checked while under normal operating pressure with either a liquid solution or a leak-detection device to locate any source of a leak.

6.22.4  Piping/Tubing Addition or Appliance Connection to Existing Piping/Tubing

6.22.4.1  An addition to an existing piping or tubing system shall be tested as an individual system in accordance with Clause 6.22, except that:
(a) where the addition is: (i) 20 ft (6 m) or less in length, or (ii) one continuous length of piping or tubing not containing fittings and the normal working pressure is less than 0.5 psig (3.5 kPa), the addition shall be leak tested in accordance with Clause 6.22.3(e); and
(b)  where the addition is accomplished using a welded tie-in, and the new system has been tested in compliance with Clause 6.22, the tie-in weld shall be tested in accordance with Clause 6.22.3(e).

6.22.4.2  A replacement appliance connection to an existing piping or tubing system where the normal working pressure is less than 0.5 psig (3.5 kPa) shall be leak tested in accordance with Clause 6.22.3(e).

Porcupinepuffer

I've never had any of these 1/2 psig valves leak, blow apart, fail, or melt under 15psig. They're more then robust enough to handle a measly 15psig. Done plenty of pressure tests with them still in place. I always disconnect from the gas valve from the appliance, for obvious reasons. I know they're not rated for that pressure, but it's momentary just for the test. If anyone asks, I removed them and capped them on the pipe when I did the test.

walker

So pretty much just use a manometer and test at working pressure for 10 minutes to ensure there is zero drop in pessure?
I'm assuming I could tie in to the gas valve inlet test port and test from there.

walker

Quote from: Porcupinepuffer on October 29, 2017, 08:45:36 AM
I've never had any of these 1/2 psig valves leak, blow apart, fail, or melt under 15psig. They're more then robust enough to handle a measly 15psig. Done plenty of pressure tests with them still in place. I always disconnect from the gas valve from the appliance, for obvious reasons. I know they're not rated for that pressure, but it's momentary just for the test. If anyone asks, I removed them and capped them on the pipe when I did the test.

I'd be lying if I said I haven't done this myself in the past.

Porcupinepuffer

It makes no sense that they could be that weak given how they're made. It's as though it's an oversight and they wrote 1/2" PSIG because it's intended to be used with natural gas and propane on the low pressure side. The manufacturer never realized we'd be doing a temporary pressure test with a higher psi. You see many other valves of the same design can easily take 100 psi to 200 psi with no issue.

Mmtc79

Propane pressure test you can use Manometer on the regulator port or unhook at reg and hook gauge on and remove valves

Admin