[ShtRnsdownhill]

I think the gas pressure went way up in low pressure lines and houses go boom...
https://www.aol.com/article/news/20...any-homes-you-cant-even-see-the-sky/23526533/

 

[dhal22]

Unusual for gas leaks not to be related to hack plumbers.

 

[ShtRnsdownhill]

Unusual for gas leaks not to be related to hack plumbers.

when you run 60 plus pounds of gas through any gas appliance made for 1/4 pound and it blows the gas valve out and fills house with gas..house goes boom....I think the gas company crewed up and put high pressure gas through low pressure service pipes...national grid just put all new pipe in the ground where I live and upgraded from low pressure to high pressure with new regulators at every house, but there is still miles of low pressure pipe in the ground, so if they made a mistake with a cross connection and sent high pressure to houses that will happen...im curious to see what the cause is from..

 

[ShtRnsdownhill]

The Massachusetts Emergency Management Agency blamed the fires on gas lines that had become over-pressurized but said investigators were still examining what happened.

 

[Plumbus]

The San Bruno fire was caused by old lines with suspect welds giving under excess pressure. And, the utility (PG&E) was well aware of the danger beforehand.
https://abc7news.com/news/pg-e-receives-maximum-sentence-for-2010-san-bruno-explosion/1722674/

 

[Tommy plumber]

I can understand a regulator not holding high pressure, but pipe is pipe. A steel pipe shouldn't break apart if pressure goes from 1 psi to 65 psi.


Something doesn't add up with this scenario. I don't think that we have enough facts.

 

[ShtRnsdownhill]

I can understand a regulator not holding high pressure, but pipe is pipe. A steel pipe shouldn't break apart if pressure goes from 1 psi to 65 psi.


Something doesn't add up with this scenario. I don't think that we have enough facts.

here on long island some of the gas lines are in the thousands of pounds of pressure, usually from national grid facility to facility, but cross connections can happen, what happened in boston are the appliance regulators blowing from the high pressure..not the pipes bursting..but some or many of the old gas main pipes are lucky to hold low pressure because they are so old...lets not talk about the water mains either..or infrastructure in the US is crumbling, so get use to more of these disasters ..its still cheaper to pay the damage than fix the system..

 

[Master Mark]

I can understand a regulator not holding high pressure, but pipe is pipe. A steel pipe shouldn't break apart if pressure goes from 1 psi to 65 psi.


Something doesn't add up with this scenario. I don't think that we have enough facts.

I am at a loss here too.... in our town in comes to the house in high pressure and gets kicked down to a few ounces through the gas regulator at the meter---

- so can the regulators blow from high pressure

or are these older lines you are talking about in the system with only low pressure going through them have no regulators at the meters in case of a spike in pressure from a cross connection???

 

[ShtRnsdownhill]

I am at a loss here too.... in our town in comes to the house in high pressure and gets kicked down to a few ounces through the gas regulator at the meter---

- so can the regulators blow from high pressure

or are these older lines you are talking about in the system with only low pressure going through them have no regulators at the meters in case of a spike in pressure from a cross connection???

on long island, the low pressure( 1/4lb) meters run straight through, no safteys incase high pressure is piped to them, just what happened in boston im figuring...national grid seems to be changing over to all high pressure mains and services with regulators, I believe the regulators have a relief valve that vents the gas to the outside incase they let loose...

 

[plumbdrum]

These were low pressure (1/2 psi) services supplied to the homes and businesses (old infrastructure) the gas valves and gas pipes became compromised with 95PSI (estimated) and filled many structures with gas.

Sad situation up here and it’s getting colder by the day.


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[justme]

I can understand a regulator not holding high pressure, but pipe is pipe. A steel pipe shouldn't break apart if pressure goes from 1 psi to 65 psi.


Something doesn't add up with this scenario. I don't think that we have enough facts.

The pipe isn't the problem it is the old ass fittings that haven't been pressure tested in forever.

 

[ShtRnsdownhill]

The pipe isn't the problem it is the old ass fittings that haven't been pressure tested in forever.

no it wasnt the fittings either, it was all the regulators on the gas equipment that were only designed for 1/2 psi, so all the diaphragms or springs to regulate the small 1/2 psi of pressure were blown out with 95+ psi and aloud the gas to just fill the houses with gas till ignition and BOOM!!!!
most pipe and fittings can withstand hundreds of PSI and be fine...

 

[plumbdrum]

no it wasnt the fittings either, it was all the regulators on the gas equipment that were only designed for 1/2 psi, so all the diaphragms or springs to regulate the small 1/2 psi of pressure were blown out with 95+ psi and aloud the gas to just fill the houses with gas till ignition and BOOM!!!!
most pipe and fittings can withstand hundreds of PSI and be fine...

All piping systems were tested prior to going back into service, some systems were probably already leaking and were totally replaced.

For a little while, existing CSST was not allowed to be reused until verifications from manufacturers.



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[ShtRnsdownhill]

so whats the final official story on how the gas mains got over pressurized? or is that top secret never to be known?...lol

 

[plumbdrum]

so whats the final official story on how the gas mains got over pressurized? or is that top secret never to be known?...lol

NTSB has taken over the investigation, more than likely human error.


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[skoronesa]

https://www.npr.org/2018/11/16/6686...-what-caused-string-of-gas-explosions-in-mass


Electronically controlled main distribution regulators opened way too much.



The guy in charge of replacing the lines shut off the flow of gas to the old cast iron line and thus the sensors which control the main distribution regulators. When he did so the sensors saw low pressure so they sent signals to the distribution hub and began opening the regulators all the way allowing high gas pressure into the still connected lines else where.











.

 

[ShtRnsdownhill]

https://www.npr.org/2018/11/16/6686...-what-caused-string-of-gas-explosions-in-mass


Electronically controlled main distribution regulators opened way too much.



The guy in charge of replacing the lines shut off the flow of gas to the old cast iron line and thus the sensors which control the main distribution regulators. When he did so the sensors saw low pressure so they sent signals to the distribution hub and began opening the regulators all the way allowing high gas pressure into the still connected lines else where.











.

it still came down to human error...and they will pay out alot in lawsuits..

 

[skoronesa]

Yeah, apparently expected to hit $1 Billion


https://en.wikipedia.org/wiki/Merrimack_Valley_gas_explosions








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[Tommy plumber]

What a catastrophe.

Sensors allowing gas to increase pressure in the distribution lines due to sensing "0" psi.

This reminds me of some plane crashes. Sometimes a combination of faulty sensors coupled with human error brings planes down in a similar fashion.

The two Boeing Max airliners that recently crashed are thought to have had faulty sensors that when the plane was flying at level flight, the sensor was detecting that the plane was climbing at too steep of an angle and therefore pitched the nose down. But when already at level flight, pointing the nose down increases air speed and sets the plane on a collision course with the ground.

Imagine the pilots fighting to control the plane but can't. Like driving your car and it is speeding up all on its own and you can't slow the car down. Very scary.

 

[PLUMBER_BILL]

gas lines bit of history

What a catastrophe.

When I started this trade the Sawsall was -- yet to be invented. My boss told me as an apprentice never cut any pipe with a hack saw, pipe cutter or anything else until you are positive the line is turned off. In a house at that time there was a lot of steel pipe. As to gas there were gas ranges, refrigerators, dryers and yes there were gas lights. hot water was made using gas fired coils piped into range boilers. Most in wall gas piping had been cut in the basement and plugged shut, but in my early years in the trade I did find about 4 properties with live gas lines in the walls. You did not see a lot of gas for heating here in Allentown gas was a by-product of Bethlehem Steel's coke ovens and it was called manufactured gas. The next step was mixed gas, that was when natural gas made it's entry into the market.