Natural Gas and Home Explosions

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If natural gas is piped into your home and pressure is lost in the transmission lines such that pilot lights go out:I assume that you shut off the main valve,but then: How do you tell if the valve is leaking? What happens if you are away from home or asleep when the pressure is lost? Will the power company have to shut down all transmission until every home and business has turned off their main gas valves?Or do they start transmission again not knowing if gas is being pumped into buildings with open gas lines?Do those buildings go boom? Could anyone cite real world examples of what could happen or did happen in disasters like earthquakes,or the power outage a couple of years ago in the NE that are non y2k?TIA

-- Desertj98 (jturner@ptway.com), August 27, 1999

Answers

About 15 years ago the temp. reached -32 here in the burgh. There was so much gas being used that there was more air in the lines than gas in some places. Warnings were on tv. Some houses did go boom!

-- FLAME AWAY (BLehman202@aol.com), August 27, 1999.

all gas installations have a fail safe regulator...if the pressure drops the regulator closes. It must be manually reset before the gas can enter the house again.

-- Ace (Ace@nospam.com), August 27, 1999.

Kobe burned to the ground in 3 days after a strong earthquake. In Japan, said to be "the most prepared."

When gas pipeline pressure goes down, pockets of air develop and travel and grow. What's to prevent FIRE from a Kaboom traveling backwards through the lines and setting the whole city on fire from underground? Jetting explosive flames out through appliances too! Please explain your understanding/knowledge of this.

Remember, low or no water pressure compounds problem.

-- Ashton & Leska in Cascadia (allaha@earthlink.net), August 27, 1999.


I read that next to the complexities of getting electric to each and every-one, the next most trouble-some grid to deal with is the gas distribution system. I recall about 12 years or so ago in a small north of Boston, mass. town were a single indiviual finishing up a connection on a gas line that distributes to a part of the town. Two lines to choose from, lets see, enee-menee-minee- moe. He choose the high pressure line to go into the low pressure line. It made no differents weather your were home or not, every house, apartment complex, and business that was connected to that line had there pilots, in stoves, water tanks, etc. act like blow tourches, shooting flames out from 5 to 15 high. By the time that one guy figured out the problem, many complexs burt to the ground...I summit find out were your meter is and if your pilots go out, go to the meter and shute off the flow until notified by gas that every thing is ok.

-- Les (yoyo@tolate.com), August 27, 1999.

Every gas valve has to be turned off before repressurizing any transmission or distribution system to erase the possibility that gas could be leaking through. Look in the front of your phone book, there's instructions on how to shutoff your gas and electricity in case of an emergency. You will need a 12-inch crescent wrench to shut off your gas meter. Most trailer parks have a master meter and someone should know where it is located. Out here in the West in past emergencies, we have gone house-to-house to shut off gas meters to make it safe. Sometimes valves leak through but it is rare. Most gas appliances anymore have automatic shutoffs so if pilots go out, the gas won't go through. Gas range pilots are so small they don't present any problem. For those of you who use propane, just remember that propane is heavier than air and will pool up. Follow the directions on relighting pilots diligently. Never put your face in front of the appliance you are trying to light unless you like burnt hair. And one more thing, your government loves you, at least that's what they keep telling us everyday.

-- Got Gas? (gotgas?@maaloxxx.com), August 27, 1999.


Ace: The only time I have seen those fail-safe type of regulators was in a trailer park. The cap of the regulator had to be removed and the chain pulled to reset the regulator. Where I am at, our domestic gas meters are not of the type you are speaking of. If pressured dropped to where it would cause a major problem. I am sure that before the gas is turned back on, that all safety concerns would be met. We don't usually like to blow up our customers, that is unless you haven't paid your bill. tee hee

-- Got Gas? (gotgas?@malloxxx.com), August 27, 1999.

Thanks to all for honest answers and not flames.

Got Gas said "I am sure that before the gas is turned back on, that all safety concerns would be met. We don't usually like to blow up our customers, that is unless you haven't paid your bill. tee hee" Thank God for small favors :-) Seriously if all have to be turned on manualy does the typical gas company have enough trained people to do it in a timely manner?How would civil unrest,curfews etc. impact on the time to get back on line?Those in northern climes need to know.Could there be such as surges wherein you had enough pressure then not enough,then enough:you get the idea.Gas and electricity are scary to those that don't understand them and need respect from those that do.Thanks again for all the good answers.

-- Desertj98 (jturner@ptway.com), August 27, 1999.


Desertj98: In looking at past situations, qualified gas people had to be imported from neighboring states to help reestablish service in a timely manner. If you want to do the math figure 20 minutes to turn each service on in your area, that would be a good estimate. It is our understanding that transmission and distribution systems have alarms in the event pressure drops too low. These things are always monitored. That is not my concern though. If power goes out, I don't see how they're going to run their compressor stations, and who knows what it will be like getting things back up to speed ITSHTF in terms of curfew and civil unrest. Police escorts? I plan to stay home and protect my own house. If the situation gets to the point that it is unsafe to be on the streets, then I don't see any electric or gas utility personnel working. As far as electricity goes, there are times when the voltages gets too high or too low, but are discovered by personnel who are on station monitoring these things. Again, know where your fuse box is and stock up on replacement fuses. It would be a good idea to unplug all appliances except for one light so you know when the power is back on. Power surges can damage appliance motors although many motors have built in protection against that. If you have to bug out shut everything off at the meters. Good Luck!

-- Got Gas? (gotgas?@malloxx.com), August 27, 1999.

My gas company upgraded my meter earlier this year. I asked the rep to show me how to turn off the gas (she had to do it anyway to replace the meter), and she was ok with that request. Then I asked her to show me how to turn everything back on. She convinced me I should ask the gas company to do it if it becomes necessary. Apparently it is far more than just restarting the pilot light. Of course, I expect there would be a long line of requests then.

-- Brooks (brooksbie@hotmail.com), August 27, 1999.

Your gas representative was correct in not showing you how to turn your gas back on and the main reason why was for your own safety. The other reason would be a potential law suit. If you were shown how to turn your gas back on and something went wrong, you could turn around and sue the gas company. When your gas representative turns your gas back on, they check all gas appliances for leaks and for carbon monoxide emission. It is a good idea to call your gas company every year for an appliance check, especially before winter sets in. In our state, the service is free. ITSHTF you won't need to call anyone.

-- Got Gas? (gotgas?@malloxx.com), August 27, 1999.


A few years ago,on Halloween, a dumb prankster turned off the gas for our little town of 5,ooo. PG&E workers came from hundreds of miles to go through the town and turn off the gas to each house/apartment. Then they had to go back and turn on the gas and relight all the pilot lights. It was days before everyone in town had the gas turned on. It got darned chilly. We had no problems with any explosions or people getting gassed.

-- Homeschooling Grandma (mlaymon@glenn-co.k12.ca.us), August 28, 1999.

Home Schooling Grandma: What a pranskter you are. Why would a prankster on Halloween come to your city and turn off 5,000 customers to each house/apartment? Do you know what it takes to do this? Either your witches brew has overwhelmed your senses, or you are smoking something that could be a marketable product. Where are you located? Your story can easily be traced and proved out....I will wait for more information.

-- Got Gas? (gotgas@malloxxx.com), August 28, 1999.

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