I am using natural gas to fire my outdoor grill. The builder left a 1/2 in. nipple stubbed out about 9 inches above ground. I attached a valve, then ran black pipe down 14 inches underground, then elbowed horizonally and used a transition fitting to yellow polyethylene pipe for fifteen feet to the edge of the patio. I converted back to black pipe, and at the surface I added another valve and a quick disconnect fitting.
All worked well for many years, but now I find I have water in the line and had to remove the disconnect fitting, turn on the gas and blow some of the water out before my new grill would burn properly. I don't believe I have any gas leaks after excavating both ends of the line. So, I am doubtful that water is somehow entering the line from the ground, as suggested by a gas company employee.
I understand there is often a small amount of water in the gas line as it is delivered to the customer. This fact I believe suggests the wisdom of installing a drip leg or sediment trap. I note this line is clearly the lowest point of my gas line piping and currently has no trap.
Question: Where do you think the water is coming from and what should I do about it? If I built a sediment trap below the nipple, coming out of the exterior wall, would it be a good idea to put a valve at the bottom of the trap, so that the water could be occasionally drained from the line?
Sounds to me like the nat gas being delivered does have a bit of water in it.
Yes, the best solution would be to have a drip leg installed at the lowest point, in fact it's now a code requirement. The drip leg should consist of the Tee, nipple (~3"), ball valve, another nipple, and then a cap. The reason for the cap is in case the the ball valve inadvertently gets knocked open, thus stopping the outflow of gas.
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