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evaristo10 (Mechanical) (OP)
28 Dec 12 3:46
Two flare stacks were reported bent at the same time at an Oil&Gas plant, most probably cause "High Temp degradation", is strenghtening them good idea as a temporary mitigation measure?
BigInch (Petroleum)
28 Dec 12 6:29
You need to turn the fire off and investigate what's left of them before you can possibly make that decision. While they're cooling off, design and get another one on order.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

SNORGY (Mechanical)
28 Dec 12 15:16
Not sure how you field-fix that. Looks like the next stack ought to be free standing, though, considering what the guy wires appear to be accomplishing in the overall scheme of things.
Helpful Member!  TD2K (Chemical)
28 Dec 12 21:44
What Big-Inch said, I'd get another stack on order as a precaution.

What sort of backflow preventer do you have on that flare stack? What about assist gas for smokeless combustion?

We had a vertical flare stack where I noticed one night the metal was red-hot at the base of the mol seal, turns out we had the center assist steam coming on first when it was supposed to come on last, apparently resulting in combustion below the tip. Changed around the order and that was the end of the problem. I heard of another 45 degree inclined flare tip up on the North Slope that had internal burning (never heard just why) until the whole thing just laid over on its side. It looks like for some reason you've had internal burning down in the flare stack.
SJones (Petroleum)
29 Dec 12 0:16
Duplicate thread to thread338-336298: Flare Stacks bent

Steve Jones
Materials & Corrosion Engineer

All answers are personal opinions only and are in no way connected with any employer.

evaristo10 (Mechanical) (OP)
29 Dec 12 2:39
Thanks for all inputs.
We are also suspecting internal burning due to problems on separators.
What about shorter the flare stacks, to remove the more affected portion of them?
Helpful Member!  poli60 (Chemical)
29 Dec 12 3:37
Shortening the stack would result in excessive radiation.
Helpful Member!  SNORGY (Mechanical)
29 Dec 12 10:58
If the surrounding body of water is permanent, I would not be all that concerned about radiation. If the stack was any shorter, it might as well be a flare pit.

Assuming you won't be able to get near it while it's flaring, I am inclined to go out there with UT apparatus and see what metal you have available to work with. If it's in any way salvageable, cut below and above the kink and weld a 2 foot piece into the middle, and remove the guy wires.

Otherwise, by visual observation of the facility in the background, I don't think I would be devoting a lot of time to coming up with a low cost fix for this somewhat toasted piece of pipe.

If shutdown outage is the issue, then in my opinion the best thing you can do at this point is take the guy wires down and let the thing last as long as it lasts. The minute you are forced to work on it, it looks like replacement is the best option.
Helpful Member!  BigInch (Petroleum)
29 Dec 12 13:05
It's the old repair it as cheap as possible philosophy again. Endemic mind set in certain regions. False economy. That's why I said get another one on order way up there at the top. A shutdown of that plant is going to cost at least 1000 x a new flare.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

evaristo10 (Mechanical) (OP)
30 Dec 12 3:55
Thanks a lot for all contributions received.
PLease have a look in the attached photo taken from the down section of the "flare stacks", it is a casing pipe 16" covering the flare pipe inside it, it seems to be more a burner than a flare stack.
TD2K (Chemical)
30 Dec 12 15:09
Is that the mother of all bunsen burners?
SNORGY (Mechanical)
30 Dec 12 18:59
Whatever it is, the outer cylinder has failed structurally and the recommendation is the same.
MortenA (Petroleum)
31 Dec 12 8:53
I also guessed its a bunsenburner type flarestack. never heard about them although i though about it. But then i got to think about that little "puff" there is when you turn off the burner in the lab and i tried to multiply this a couple of thousand times....

@evaristo10: Do you know if it is a bunsenburner - and have you been around when you turn it off?

Best regards

evaristo10 (Mechanical) (OP)
31 Dec 12 9:08
Hi MortenA, no technical information is available and I've never around when it was turn off.
I'm planning a close visit to check about three pipes coming inside the stack.

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