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I had got a permit to extend my existing gas line to my kitchen so that I can change my stove from electric to gas. I got the plumber to get the new line to the kitchen. Once the new line was completed, I shutdown the values of the gas to other appliances in the house.
I got a new gas gauge to check if the gas line holds to 10PSI as per the code. When I plugged in the gauge to the new gas line and opened the main gas value, I checked with my plumber to see if there are any gas leaks using soap+water and there was no leaks on the new pipes.
But when I checked the gas gauge, it remained at 0 PSI. I pressed on the knob on the side of the gas gauge and I could smell the gas flowing into the gauge.
Can someone please tell me how to go about the gas pressure testing procedure that needs to be done for inspection?
I checked couple of discussions and I would like to confirm if my understanding is right.
1. Pump up the gauge to 10 PSI by injecting air via the small knob with the help of the hand pump (which we use for pumping air into the tires of the car or any other vehicle).
2. Once the pressure reaches 10PSI., close the knob and connect the gas gauge to the gas line (after shutting down the gas value)
3. Once the gauge is connected, open the gas value and check if the gauge holds steady at 10PSI for the next 10-15mins with the inspector onsite.
4. Check for leaks on the existing gas pipe for any leakages.
If these steps are right, how does the guage remain at 10PSI, after I pumped air in it? I mean how do we know that the gas flow is keeping the 10 PSI and not the air I had previously pumped in via the air hand pump to keep it at 10PSI in the first place?
Please let me know your comments and thoughts and let me know your suggesstions.
You turn off the gas valve, either at the meter or where it comes into the house. Also turn off the valves at any other gas appliances you have. Install the gauge onto the line. Pump up the pressure on the line to the required pressure. Wait for the inspector. You don't open the gas valve. The gas line has only about 2 or 3 lbs of pressure on it. If you open the valve at the meter, the air you put in your piping will simply go up the gas line and the pressure will return to the 2 or 3 lbs. of the system. I don't know what kind of gauge set up you purchased but it sounds like you have a gauge, a valve for pressurizing, and a shut off valve. Install the gauge on the system, open the shut off valve and then pressurize the entire system.
When testing gas at 10 PSI you need to DISCONNECT the gas meter and spin it so the meter bar outlet can be capped/plugged. If you don't do this, most likely, the diaphragm at the meter will burst due to the excessive pressure introduced...remember, these meters are only meant to carry 1/2 PSI...
Then you are supposed to disconnect all the other appliances at the union fittings and cap off each line. Why? The same reason as above...at 10 PSI if a shutoff fails it could blow the diaphragm of the gas valve at the appliance...an expensive mistake to fix if it occurs!
Then you would install a shutoff and then the test appuratus at the appliance/piping to be tested.
With the shutoff open, pump the pressure to 10 PSI and then shut the shutoff off. Wait 10 minutes and open the shutoff...any change in the reading on the gauge?? If so, a leak is present and will need to be found by pumping the pressure to say 25 PSI and then soaping all up to find it.
Be careful NOT to pump the pressure up with the shutoff closed as that will simply blow the guage....always check to be sure the shutoff is open.
Anyway, that's how we test here in Boston where we are all licensed plumbers and licensed gas fitters.
Since he is really only testing the additional piping, can he just turn off the valve where the line comes into the house?
I guess a better question would be, shouldn't the plumber doing the work have set this up?
The main gas shutoff is installed on the inlet piping to the gas meter. In this case, if he only shuts the inlet shutoff he would be testing right through the gas meter (via the outlet piping) and at 10 PSI could burst the diaphragm as mentioned. There is almost never a shutoff on the outlet side of the meter. If there was an outlet shutoff then shutting this would work fine...as long as the shutoff gets completely closed off and even that is a bit of a guess with older shutoffs so we are taught to ALWAYS disconnect the meter. Fact is that if a gas company determines that a diaphragm got burst due to excessive pressure then the homeowner or plumber pays for it.
I know this all sounds like overkill, but it is how to test a gas system at any pressure without blowing the diaphrams to any gas meters or gas valves...
For example, if he determined a leak is present using this method of testing, then he could simply pump pressure up to 25 or even 50 or more PSI with no concern for hurting any appliances.
I really only wanted to present a correct testing method for future readers...
I would also agree that the plumber should have performed this test!
Just want to recap what I had seen in this discussion. Many thanks to Mark, Harold for valuable inputs.
1. Shutdown the values to all the appliances in the house including the new gas line to kitchen.
2. Shutdown the main gas value.
3. Connect the gas pressure gauge to the gas line.
4. Pump in upto 10PSI on the gauge from the knob provided on the guage.
5. Verify if the gauge is holding good at 10PSI.
6. Open the main gas valve to the house.
7. Open the gas valve of the kitchen and check if the pressure is holding good at 10PSI for 10-15 mins
8. Check for leaks on the line.
9. Open the gas valves to other appliances to see if the gas pipe is not leaking else where.
10. Once the gas pipes are checked and verified for no leaks, then shutdown the gas valve on the kitchen and remove the gas pressure guage and connect the new cooking appliance to the gas pipe.
Do not open valve to meter with 10 lbs of pressure on piping.
Mark has just explained that that much pressure will damage meter.
You can only do this if you have a shut off valve between you and the meter. In other words only if you have valve to turn off gas inside the house. And only if you have valves at each appliance to turn off gas to that appliance.
You are pressurizing the piping, the piping only, to see if you have a leak.
Are you doing this for an inspection or for your own satisfaction?
Most important here is to stop mixing the gas and air...not necessary and will damage something costly if you keep doing it!
Follow this list and you should be all set:
1) Disconnect the meter from the meter bar and cap the outlet as directed at post #3...see image again. This is critical to success.
2) Disconnect all union fittings to each gas appliance and cap these (remove the 1/2 union fitting and cap line). You could also shut off the shutoffs, but as stated earlier, if you have a leak past a shutoff it could damage a gas valve or even damage the appliance.
3) Install test apparatus with shutoff and guage at new piping to appliance.
4) Pump the system up to 10 PSI and hold for 20 minutes. Once confirmed all is OK you will need to schedule for inspection.
5) Pump system back uyp and stand for inspection....pass inspection...
6) After the inspector signs off on the test you can depressurize the system by opening the shutoff at the appliance and removing the test apparatus (do this slowly).
7) Reconnect the gas meter and all the appliances (or turn on shutoffs you shut off).
8) Double check all connections that you disturbed to be sure ALL unions/fittings have been re-tightened.
9) Turn on gas at gas meter now.
10) Bleed gas off at the farthest appliance by loosening the union fitting until you smell gas (shouldn't take too long). Re-tighten union. This expidites lighting the pilots.
11) Bleed off gas in same manner as above at any appliance you disconnected. Be sure to let gas dissipate before lighting the pilot(s) in next step!!
12) Light pilots or test that stoves ignite at each burner, etc.
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