Gas line blockage

[jlckmj]

Has anyone experienced a natural gas line that gets blocked with condensation and stops flowing?

I have in floor heat in my garage and the natural gas water heater quit running. I tried to restart and found that I had no gas coming in to the pilot light. I took off the gas line drip leg just to see if it was the line or possibly the gas valve, and there was nothing coming out of the line.

I remember when we hooked up the system for the first time (about 4 months ago)we had to blow the gas line out with air in order to get about half a gallon of water out of the line before we could get gas to flow to the garage. I thought at the time that we had to do that because the line sat under ground for almost a year prior to hooking up the heater.

The garage is about 35 feet from the house, and the gas line is buried 40 inches below grade with about 50 to 55 foot total length. There is about 2 foot of black pipe gas line exposed above ground at both ends connected to direct burial flexible pipe covered in the grey PVC type covering.

But I was wondering if this is a normal occurrence, or do I have other issues to get worked out to keep from having to do this every year?

thanks, Jim

 

[Milton Shaw]

Water in the line is not normal. I would cap line and pressure test line to make sure it's not got a leak that is letting in standing water in the ditch get into the line. I had an air line that when not under pressure would fill with water from underground water pressure. Gas pressure is so low that it doesn't take much standing water to generate more pressure than the 4" wp that that line normally has. If standing water in ditch was 12 inches deep then that's three times the line pressure.

 

[CNGsaves]

Sounds like this water incident is your WARNING SIGN that your gas line is improperly installed. Soon that line will be rusting through and you'll have an explosion on your hands!!

Standing water and buried black pipe steel do NOT mix.

Need to yank out that buried black pipe steel and replace with yellow polyethlene plastic pipe with risers on each end of the connection. The continuous plastic buried yellow pipe will not allow any water to get in. Improve drainage so that each end where risers connect are in dry soil.

Be safe and fix that faulty NG line.

 

[BD1]

You may want to call your natural gas supplier. Water in a gas line is not normal.

 

[brewchief]

There is about 2 foot of black pipe gas line exposed above ground at both ends connected to direct burial flexible pipe covered in the grey PVC type covering.

Sounds like this water incident is your WARNING SIGN that your gas line is improperly installed. Soon that line will be rusting through and you'll have an explosion on your hands!!

Standing water and buried black pipe steel do NOT mix.

Need to yank out that buried black pipe steel and replace with yellow polyethlene plastic pipe with risers on each end of the connection. The continuous plastic buried yellow pipe will not allow any water to get in. Improve drainage so that each end where risers connect are in dry soil.

Be safe and fix that faulty NG line.

Read again CNGsaves, as far as I can tell from here it sure sounds like it's already plastic and the grey pvc covering is the riser at each end.


If the ends were left open I can see enough water getting in to cause problems for a long time. I also would agree that it is possible that it could be leaking and allowing groundwater in, pressure test would give a quick answer to that.

 

[CNGsaves]

I'm guessing some sort of jerry rigged CSST . . . . OP calls it
"direct burial flexible pipe covered in the grey PVC type covering"
. . . . never have seen yellow polyethlene plastic pipe covered in PVC !!

First call anyway SHOULD HAVE BEEN to the Gas Company . . . not GJ.

Please OP call the GasCo and take some pics of this line so GJ forum can give you better answers.

Good luck . . . but Be Safe!!

 

[BD1]

Gray PVC ? I wonder if someone used electrical sealtite ?

 

[jlckmj]

Hey guys,
thanks for the taking the time to answer.

The pipe was put in by a licensed plumber, it is the proper pipe for direct burial, I checked today with him on that. The grey pvc cover is the stand pipe (or riser) part on both ends. When it was first hooked up there was standing water in it from sitting for over a year with nothing hooked to it. The pipe had to be blown out at that time to get gas to the appliance.

I disconnected it today and blew about a quart of water out of the pipe into a bucket. That does seem like a lot of water, but I am not sure, that is why I posted the original question.

The water could have been there before, or it could be from condensation due to all the heating and cooling we have had recently. about 2 foot of the black pipe sits in direct sunlight on both ends and heats and cools everyday.

My best guess is that it is a combination of water that was left in there, and the condensation. The plumber feels that the pipe in the ground has a low spot and the water pools there eventually blocking the gas flow.

Either way I am not happy with it, and will be requiring a pressure test to make sure it does not go boom.

thanks, Jim

 

[CNGsaves]

Sorry to tell you that "licensed plumber" is giving you the boondoggle!!

No low spot for a buried gas line should be getting ANY water like that. Pipeline quality natural gas can only have moisture in PPM (parts per million) and in no way would ever accumulate a quart of water in a year.

So you've now pulled 1/2 gallon previously, and now another quart of water from just a 50 ft buried line?? How can that be??

Please let us know what material that was used for that buried gas line.

That much water is going to rust out your entire line and any equipment that is connected to it - - thus your $500 heater on the end will soon be junk. This is NOT SAFE!

I strongly suggest you get 2nd opinion from the Gas Company and/or another plumber who is familiar with buried natural gas line.

Be Safe . . . I'm worried about your safety, and your family, and your neighbors!

 

[philjafo]

It sounds like you just didn't get all of the water out the first time it was blown out and it eventually collected in a low spot enough to block it again. I don't think a normal household air compressor would be able to move enough air to get all of the moisture out the first time. Do a pressure test and if it shows no leaks run it for a while. If it gets blocked again I would call up a company that winterizes lawn sprinkler systems. They have engine driven air compressors capable of getting all the water out. Another option would be to put a vacuum pump on the line for a few hours, that would cause any moisture to boil and get pumped out.

 

[CNGsaves]

It sounds like you just didn't get all of the water out the first time it was blown out and it eventually collected in a low spot enough to block it again. I don't think a normal household air compressor would be able to move enough air to get all of the moisture out the first time. Do a pressure test and if it shows no leaks run it for a while. If it gets blocked again I would call up a company that winterizes lawn sprinkler systems. They have engine driven air compressors capable of getting all the water out. Another option would be to put a vacuum pump on the line for a few hours, that would cause any moisture to boil and get pumped out.

Unless the OP is trying to use a pancake compressor or something way too small, a decent-sized compressor would be more than adequate to blow out any water in 50 ft buried line (assuming the line has interior smooth surface).

Every year I've blown out my sprinkler system with normal compressor - - ie my buried sprinkler system lines have hundreds of feet of buried plastic pipe. It has 6 zones and normal compressor blows the sprinkler lines totally free from water during winterization step in Fall each year. This year used my neighbor's compressor (33 gallon Craftsman) and winterized both his sprinkler system and mine back-to-back and that compressor did fine.

Once we find out what material the OP gas line is made of, and info back from the Gas Company, then will know better what is problem. Gas companies bore under streets, creeks, etc where there may be standing water all the time and their gas lines don't fill back up with water once gas line is operational. After installation a gas line should never have water getting back in there. Sounds like OP has water leak getting INTO buried gas line which IS a major problem.

 

[BD1]

50 feet of one inch pipe holds 2.5 gallons if filled with water.
What size is it?
I do not know of a PROFESSIONAL that would install a gas line and leave it open exposed to the elements. Not to mention, it should have been capped off to pressure test BEFORE gas service was activated. There is no way you should have water in a underground gas line or any line for that matter when installed from new. This plumber is used to doing sewer lines so water doesn't matter. He should be reported if he did not follow good piping practices.
If you decide to pressure test the underground piping, it must be disconnected from the system. You don't want to blow your regulators . If you don't know, your gas piping doesn't even have one pound of gas pressure. You may have 7 to 10 inches. One pound pressure is about 28 inches water column.