Water tank explosion....yes, a water tank 4

[fel3]

https://www.yourcentralvalley.com/n...tures-deadly-water-tank-explosion-in-lemoore/

This happened in my area. I am very familiar with Lemoore and its water system because twice I was at firms that served as the contract City Engineer and I have designed some elements of that water system. My first stint was long before the Well 7 site was developed. My second stint was after the well and first tank at this site had been constructed. I helped the engineer who designed the water treatment vessels and second storage tank at this site sort out some piping connections, but I can't tell you if it was the older or newer tank that just blew up and my records are in storage.

Apparently, someone was welding something to the outside of the tank and it sparked flammable gas inside the tank (that's what the City's Public Works director speculated about in an on-site interview I saw online). This tank appears to have had a good amount of water in it, so I'm having trouble understanding how a flammable gas got into the headspace of the tank. More details will certainly come in the next days/weeks/months.

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"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

 

[Demented]

Outside or inside, doesn't matter. The liner itself of the tank should have raised enough concerns for the atmosphere testing. Methane is also very common in ground water supplies, especially in certain geographic locations, and is a danger that should always bee considered and tested for. In safety stand downs due to unfortunate events, we've gone over the dangers of welding in such conditions. 2009 was the last big thing that forced the issue in the industry again. That was a waste tank at a potato processimg plant blowing up becuse of microbial farts that were undetected in a water filter.

If there is no proper way to test, no propery way to drain, no way to vent, or no way to examine the liner,

STAND DOWN.

Ground and waste water should always be tested because of this known condition that is known to become exosive in confined spaces.

 

[JStephen]

Normally, steel water tanks do have a roof manway, so it is possible to check the atmosphere.
On a tank like this, even if "full" of water, there would still be a lot of vapor space above the water, and the same hazard would exist, perhaps to a lesser degree.
This has happened in other water tanks, so not an unknown occurrence.
On the odor issue, hydrogen sulfide has a LOT of odor, and if you have enough in a tank to blow it up, you'd likely have all kinds of complaints about smells from the tank and from the water also, so one reason for assuming methane rather than hydrogen sulfide.

 

[itsmoked]

FYI JStephen; At a high enough concentration hydrogen sulfide becomes odorless, though that's likely not going to occur in a water-well situation. Also, you'd likely come thru a zone of lower concentration when getting to the higher concentration.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[JStephen]

Right, but if you had a high concentration in the tank, you'd have low concentration all around the neighborhood and in the vicinity of the tank itself, as well as smells in the water.

 

[waross]

My H2S courses taught us that higher concentrations do not become odourless but do kill the sense of smell.
disclaimer: The main purpose of the tests was to provide the company with provable due diligence.
"It is unfortunate that the worker dies, but we did give him an H2S awareness course."
Anyone who could stay awake for at least 3/4 of the course could pass the test.
Accuracy of information was not a high priority.

Bill
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Ohm's law
Not just a good idea;
It's the LAW!