Gas Pipe Install

[Phil Yarbrough]

Teflon tape is best not used on gas. Small pieces end up in the gas valve.

[John Gilmer]

With pipe threads that definitely is part of the secret. The threads are tapered as as you tighten you deform both male and female threads to make the connection.

The "dope" helps with ordinary joints by making it slightly easier to really, really tighten down and then sealing the tiny residual leak.

Like it or not, some joints can't be tightened down until they can't be turned anymore. Elbows and "T"s must be oriented. The plumber has to judge by the resistance when he only has "one turn" left and then stop when the fitting is "pointing" in the right direction. It's when you can't really tighten things "properly" that you need the high quality pipe dope. That's not the case, of course, for joints in a long string of course.

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[m Ransley]

1.1/4" on my 117000 btu unit is needed over I believe 30 ft. I dont know what btu or lenght run you have but I hope you followed a piping sizing sheet, One came with my Bosch . These units will easily double your home gas usage, a manometer is the only way you will be able to predict if when on the coldest days of the year when Ng pressure might be lower if you will be ok with competing apliances on. I can measure a temp drop when only my 70000 btu furnace kicks in. Who knows, even your main supply could be poor. Testing is the only sure way to know, you can buy a manometer for maybe 40$

[hallerb]

how did you seal the far end. I mean you pressurized one end, what about the other?

if you have that end connected to the heater thats probably the leak! appliance valves are NOT designed to hold back that kind of pressure.......... normal pressure a few ounces test poressure 25 to 75 pounds.....

other end should be capped and sealed for proper testing...

[John Gilmer]

Fortunately, there is a pressure regulator at the gas meter. Unless you have a real problem with the supply, you actually will get MORE gas delivery after the meter during cold weather.

(I take it you mean a pressure drop.)

Frankly, that's not a big deal. Today, just about every gas consuming appliance has its own regulator. The "local" regulator accepts the gas from the meter (regulated to perhaps 11" to 20") and reduces it to what the appliance jets require which might be at little as 1/2" (H2O) gas pressure.

I grant your point that when a 120 BTUs/hr furnace kicks in it's a MAJOR drawn on the gas supply.

Gages that can read pressures equivalent to a few inches of water can be both expensive and delicate. If you are comfortable around gas lines you can just put a plastic tube on a tap and either partly fill a "U" with WATER and observe the difference or just stick the end of the tube into a deep container of water and observe how deep down the tube is when things start/stop bubbling.

[Kurt.Soenen]

one end is capped and the other is fitted with an appliance gas valve. I was always suspicious of that ball valve and pressure testing, so I'll probably remove it and replace with a cap and then pressure test again. But I think the problem is a joint that was not tight enough and the dope failed. That's why there was a delay in the leak

Anyway, when do you call it good? Maybe I will first pump the system up to 15 psi for 10 minutes to satisfy the inspector. Then I will reduce pressure down to 5 psi and let it sit for 96 hours before I'm personally satisfied and feel like I can move on.

Thanks for the > how did you seal the far end. I mean you pressurized one end, what > about the other?

[hallerb]

probably right but before you tear it all apart try capping at that valve just for the heck of it