Massachusetts gas fires: Another technological tragedy • Hacker News Board

Re: Massachusetts gas fires: Another technological tragedy

#71

Post by adrianN » Sun, Oct 21, 2018, 7:34 AM UTC

URSpider94 wrote: post #36

nicoburns wrote: post #28

Earlier quoted context omitted.

With natural gas incidents, the entire surrounding area doesn't become unusable for hundreds of years...

No, but over the past 50 years, we’ve had two severe nuclear incidents resulting in any kind of long-term environmental damage (Fukuhima and Chernobyl), and Fukushima will be remediated within a decade. In the mean time, we’ve had Exxon Valdez, Deepwater Horizon, Andover, San Carlos, CA, plus oil trains burning down entire towns, coal mine explosions, two Gulf Wars, and sea level rise due to global warming. Pick your…

We also have burning coal mines that slowly eat whole landscapes like in Centralia https://en.wikipedia.org/wiki/Centralia_mine_fire

Re: Massachusetts gas fires: Another technological tragedy

#72

Post by jacquesm » Sun, Oct 21, 2018, 8:03 AM UTC

patcheudor wrote: post #52

What I still don't understand is why the pressure regulators and over pressure valves on the house gas meters didn't kick in? Were the homes involved so old that the meter protections failed or weren't there in the first place? It seems that ultimately you've got to have failsafes at the homes themselves. Without such failsafes, what would stop a bad actor from purposely over pressurizing a residential branch?

Those regulators work within a set range of input pressures, and need a certain delta to work properly. Over-pressure them severely and they will simply fail, and most such failures will lead to gas escaping from the regulator body. That is why you will usually find them outside of the premises they protect so they vent into the outdoors rather than into some enclosed space.

As for your bad actor: what would he pressurize your lines with? An air compressor? He'd have to dig up the lines or disconnect them first and gas from the line would likely escape in quantities large enough to discourage such tricks.

Just like in theory you could disconnect the mains from a house and then send a high voltage pulse down the feed lines, in practice pranksters and miscreants tend to avoid doing stuff that might get them killed instead.

Re: Massachusetts gas fires: Another technological tragedy

#73

Post by Scoundreller » Sun, Oct 21, 2018, 8:10 AM UTC

xenadu02 wrote: post #41

jefftk wrote: post #21

Earlier quoted context omitted.

There are pressure relief valves, but they (a) can't handle that much overpressure and (b) many of them are located inside the houses (at the gas meter, which on many houses around here is still indoors).

This is why all the new gas meters in SF have their relief vents piped outdoors - much lower risk of explosion. If you see those little squareish-looking pipe ends with a fine screen mesh on the end that’s what they are.

Why not install the new gas meter outside? Or do you mean replacement gas meters?

Re: Massachusetts gas fires: Another technological tragedy

#74

Post by pjc50 » Sun, Oct 21, 2018, 8:29 AM UTC

jacknews wrote: post #9

I realise this is beside the point of the article, but gas distribution seems like an obsolete and dangerous technology to me. For cooking, induction, for heating, heat pumps.

At the moment this is also 3x as expensive to run, and the only way that gap will close is curtailment of gas exploration and fracking.

Re: Massachusetts gas fires: Another technological tragedy

#75

Post by YeGoblynQueenne » Sun, Oct 21, 2018, 8:52 AM UTC

hyperion2010 wrote: post #60

spongo wrote: post #54

Earlier quoted context omitted.

I'm curious: within which field are you doing this PhD? I could see you as a computer scientist, systems designer, political theorist, perhaps an economist or philosopher. Is any of your work available to read online?

I'm technically in neuroscience, neuroinformatics more specifically, but was raised by a political theorist. Unfortunately I have a bad habit of writing code rather than prose, and don't keep a blog or similar, so the first thing that I could point you to would be my thesis, which is still months away.

Well, hurry up then :)

Seriously, this sounds like a very interesting subject. Best of luck with your thesis writing and submission (mine's still a couple of years away).

Re: Massachusetts gas fires: Another technological tragedy

#76

Post by akiselev » Sun, Oct 21, 2018, 8:53 AM UTC

btown wrote: post #48

taliesinb wrote: post #3

The Chemical Safety Board produces some pretty fascinating videos that reconstruct the chains of events that led to large industrial accidents in chemical plants. The videos normally conclude with recommendations for voluntary actions industry can take to prevent similar incidents in future. They basically summarize the results of detailed investigations by CSB agents. The videos are well produced and, apart from tho…

Why are these actions voluntary? Shouldn’t there be regulations that at least ensure we don’t make the same mistake twice?

In some cases it allows the agency to operate freely regardless of the political environment and in others, there are historical reasons for the way they operate (ala NTSB and FAA).

It also allows the market to decide what risks justify the cost and which ones don't via the insurance market. These advisories are front and center in lawsuits when dealing with repeat occurrences so the pressure comes from economic forces. Thankfully, there are limitations to what the market is allowed to decide so this may eventually become a regulation through public pressure or agency review.

Re: Massachusetts gas fires: Another technological tragedy

#77

Post by scotty79 » Sun, Oct 21, 2018, 9:03 AM UTC

What I see in those incidents is severe lack of backup sensors.

Why after switching to new pipe nobody checked/could check the pressure in it?

Why there were no other kind of speed sensors on a plane, simpler, less accurate, slower but not that vulnerable to icing?

Why in Three Miles Island incident why people couldn't double check if reactor has water in it or not?

Re: Massachusetts gas fires: Another technological tragedy

#78

Post by sschueller » Sun, Oct 21, 2018, 9:03 AM UTC

lutorm wrote: post #56

patcheudor wrote: post #52

What I still don't understand is why the pressure regulators and over pressure valves on the house gas meters didn't kick in? Were the homes involved so old that the meter protections failed or weren't there in the first place? It seems that ultimately you've got to have failsafes at the homes themselves. Without such failsafes, what would stop a bad actor from purposely over pressurizing a residential branch?

What would those devices do? A pressure regulator is designed to handle a range of input pressures. If the pressure really got 75x higher than the design pressure, the regulators probably just failed.

Are there really no pressure release valves that will blow out at a certain over pressure? Like a spring release that will give way and release all of the gas outside the house.

Re: Massachusetts gas fires: Another technological tragedy

#79

Post by pedrocr » Sun, Oct 21, 2018, 9:28 AM UTC

wmoser wrote: post #46

mcguire wrote: post #37

Earlier quoted context omitted.

NaK-air? Doesn't NaK catch fire in the presence of air?

Probably a giant radiator. Lots of equipment that is “air cooled” has an intermediary coolant that is actually cooled by air over a heat exchanger (radiator).

That's confusing. "Air cooled" usually means exactly that there is no "intermediary coolant". At the end of the day almost all equipment cools to the atmosphere after all. The difference between liquid cooled and air cooled cars/bikes is exactly that extra equipment of coolant lines and radiators versus just having airflow directly over the things you want to cool.

Re: Massachusetts gas fires: Another technological tragedy

#80

Post by ip26 » Sun, Oct 21, 2018, 9:34 AM UTC

patcheudor wrote: post #52

What I still don't understand is why the pressure regulators and over pressure valves on the house gas meters didn't kick in? Were the homes involved so old that the meter protections failed or weren't there in the first place? It seems that ultimately you've got to have failsafes at the homes themselves. Without such failsafes, what would stop a bad actor from purposely over pressurizing a residential branch?

Supposedly, old lines like these are low pressure lines to the house. Thus nobody has a pressure regulator in their home. It seems crazy today but these lines are antique, from the days when electrical wire was run by knob-and-tube.