Dean Romig please check in

[Southpaw]

That is probably wise advice.

[Dean Romig]

After I brought gas into the house about 6 years ago I decided to get the plumber back in to run a line to the grill on my deck. That all went well and then I was working on building my new gun room and I called him back to run another line so I could have a gas heater in the gun room. He always tested everything with soapy water and pronounced it fine so I began sheet-rocking the room. I never disturbed any of the gas pipes but the next morning when I went to continue working on the room I smelled the very faint smell of gas... or else a mouse had died in a wall...
Anyway, I called the plumber back and he couldn't smell it. He called his younger helper in and he thought he could detect a faint smell.

They spent the next hour looking for a single tiny bubble in one of the three joints they had installed... but there it was - a 1/8" bubble would show about every three or four minutes.

Problem solved. I have a very sensitive nose for such things and I don't thing a gas leak would ever get by me.




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[Mike Poindexter]

For what its worth, the natural gas into my meter through a 1 inch yellow corrugated underground line is at 6 psi, they tell me. There is a diaphragm pressure regulator that is about 7 inches in diameter and 1 inch thick that adjusts it down before it goes into the meter and then the house. The Public Service gas guy says that they normally set the regulated pressure into the house at .5 psi, but in all-gas homes they can set it as high as 2 psi. My oven is electric, but my cooktop is gas, my boiler is gas, my dryer is gas, my water heater is a sidearm off the boiler, my garage heater is gas, and my three fireplaces are gas inserts. I need the 2 psi. Gas service so far has never been interrupted, unlike electricity which goes out occasionally. If the pressure ever spikes enough to blow out the regulator, then I'm SOL. If a forest fire comes through, hopefully I wont be here when the meter blows. Wonder if they shut off the gas to an area when a forest fire is imminent? Glad you dodged the bullet, Dean.

[Dean Romig]

I hope they’re not still in use....






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[Richard Flanders]

At some point someone will get some house appliances that are leaking repaired and then will know what exactly is failing. A leak under a sidewalk is not going to fill a house with gas and blow it up. Even if the leak breached the ground you could light it and it would just cause a flare; it wouldn't explode as long as the line is pressurized. Something inside the houses is failing, something in the appliance; just not sure what. could be a regulator or a gauge. Something. "Old lines" are still going to be iron pipe so can take a LOT of pressure. Unless they fail inside a house, which is very unlikely, they would not cause a problem to a house. All my furnace work has been with oil units so I'm not familiar with gas hookups. I can only imagine that the 'overpressure' was one hell of an overpressure to have caused all this trouble. All of these things have safeties too; if the pilot light goes out a sensor cools and the gas feed is shut off. Perhaps that shutoff is a flimsy unit and gets blown out somehow. I'm really curious and hope that all the gritty details are eventually revealed on this screwup.

On a side note; The buried 10/8-inch stout steel pipeline up here that feeds the 14,700HP Rolls Royce turbine engines that turn the pumps at the first four pump stations along the Trans Alaska oil pipeline operates at 1090psi for 149 miles and feeds 3 pumps. Each turbine eats up 4.3million cu ft of gas per day. They've been running for over 40yrs and have never been replaced or rebuilt and the buried gas line has never suffered a failure.

I like Deans 'good nose' story. Don't ever ignore your nose on that one! I sat up in bed a few wks ago at 0400 and noticed a faint diesel smell. I shot up and went into the basement, two stories down, and had a internally defective and leaking low-pressure gauge I had put on to test the line pressure to my monitor heater. Thanks Beijing. What a mess. I had to pull a sheet of CDX plywood paneling off the wall(screwed on fortunately), cut 2ft off the bottom and replace it as it was soaked with diesel fuel. The concrete floor and some of a block wall got several scrubbings over several days with boiling water and a combination of Dawn dish soap, Oxi clean, and an industrial engine degreaser before the odor abated. I never ignore my nose. I can't tell you how many times I've awaken in the middle of the night and smelled something that just wasn't right, and not once have I done this and not found an issue. An iron pan left on the gas range on low and burning dry, or on the wood stove, or the wood stove overheating. Once my roof in a small remote cabin was smouldering from dripping creosote and about to burst into flames. That woulda been fun, I can tell you. Had I waited 30 more minutes to wake up it would likely have been to a blazing roof 3ft above my face.

I guess the lesson is: If something doesn't smell right, there's a problem.

[Dean Romig]

I had no idea the pipeline operated under such extreme pressure. What is the i.d. of that 145 mile length of pipe?.... and is the oil heated in order to facilitate an easier flow?





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[Richard Flanders]

The small gas line starts at 10" in Prudhoe at PS1, necks down to 8" after 34mi and terminates at PS4 149mi south of Prudhoe. I corrected the pressure; it operates at 1090psi and has a design max of 1335psi. And the turbines driving the pumps use 4.3mcf/day, not 2.8. The oil pipeline is 48" in diameter and operates at up to the design max of 1180psi. The oil is injected in Prudhoe at 116degF and is 66degF when it reaches Valdez after 8.6days en route at 3.9mph. Pipeline friction, which is controlled by injecting a polymer drag reducing agent, keeps it warm; not sure if they warm it prior to injection into the line. When full, the line holds 9,059,057 bbls of oil. The maximum avg daily throughput for the line was in 1988 when just over 2mill bbl/day were transported. Today it's down around 600,000 bbl/day, though some recent major discoveries on the slope will be ramping that back up significantly and will, despite the dire predictions for at least 25yrs of the impending death of the pipeline due to a lack of supply, keep it going for a very long time.

[Dean Romig]

Thanks Richard - excellent information!





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