Monitoring a leak through pipe crack
Monitoring a leak through pipe crack
(OP)
Good day all,
Currently on my facility there is a steam line that operates around 600 psig and 700F which has a 2 inch long circ. crack on it.
So its obviously a safety hazard and there is a plan to repair soon. However until that time I was mandated to take noise readings as a measure to show that the leakage rate is not increasing.
My question is essentially based on anyone's experience what is the nest way to monitor a leak ? (I personally don't understand the logic of just taking an overall dB measurement and saying that louder = more leaking when I think the flow dynamics and the crack geometry, material and so on are too complex for something that simple - you can correct me if I am wrong in my thinking)
Currently on my facility there is a steam line that operates around 600 psig and 700F which has a 2 inch long circ. crack on it.
So its obviously a safety hazard and there is a plan to repair soon. However until that time I was mandated to take noise readings as a measure to show that the leakage rate is not increasing.
My question is essentially based on anyone's experience what is the nest way to monitor a leak ? (I personally don't understand the logic of just taking an overall dB measurement and saying that louder = more leaking when I think the flow dynamics and the crack geometry, material and so on are too complex for something that simple - you can correct me if I am wrong in my thinking)





RE: Monitoring a leak through pipe crack
RE: Monitoring a leak through pipe crack
" a steam line that operates around 600 psig and 700F which has a 2 inch long circ. crack on it"
Failure of a line like this would almost certainly lead to injury, maiming or death. This appears on the face of it to gross negligence on the part of the management team.
To allow it to continue to leak is unheard of in the modern world. Is there no safety department there?, no government inspector or authority?
Noise is no indication of mass, only velocity as it emerges. As the crack increases then it might get "louder" or quieter.
There is no best way to monitor a leak, only a plan to fix it without delay. Leaks from glands and flanges / mechanical joints might be tolerated, but "cracks" are inherently unstable and do not grow at a steady rate.
I realize you're in a poor position to insist on anything, but I would still put your concerns in writing to someone and print and keep a copy.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Monitoring a leak through pipe crack
(We do use clamps though in case you though!)
But I suspect that soon we will fix the problem once someone higher than the upper management understands the implication of the worst case scenario of overpressurization or occasional loads.
RE: Monitoring a leak through pipe crack
A star for you. And a jail mark for Nova Star's Safety gurus.
RE: Monitoring a leak through pipe crack
More than fair haha
RE: Monitoring a leak through pipe crack
But yeah, leak that big, fix it. And hard barricade a fairly large space around it until you can get it isolated/repaired.
Nathan Brink
RE: Monitoring a leak through pipe crack
For something like the old "we can't shut it down" line is simply not relevant.
Can you get us a photo ( from a safe distance) ?
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Monitoring a leak through pipe crack
They're basically trying to keep the facility online until a predetermined shutdown next week.
RE: Monitoring a leak through pipe crack
You need to give them a message. I will call them for you, if you don't feel it is appropriate for you to do so.
RE: Monitoring a leak through pipe crack
The idea of a bolted box (clamp) type temporary leak repair is ok, but not without due consideration for the mode of failure. In this case, the OP NovaStark has identified it as a circumferential crack. With an unsound (sorry, couldn't resist!) means of monitoring crack propagation, putting a simple bolted box on would be insufficient. One must either design the connection between the box and pipe to transmit the longitudinal load, or install separate strongback devices to restrain the pipe from pulling out from the box longitudinally. That's a long way of saying "Read ASME PCC-2 Article 3.6 with a focus on paragraph 2.2" In that article, you'll see words like Therefore, leak clamps shall not be used when cracks are present, unless... That's a "shall" not a "should" statement for a pretty good reason.
RE: Monitoring a leak through pipe crack
But clearer heads prevailed and the system was shut down to repair it this evening. But I really wanted to know if that noise thing was actually done in other parts of the world, I thought I was going insane going against a well known practice. But just for information purposes, the cracked pipe is on a Tee with the branch having the crack. The branch is connected to an RV which lifted and soon after the crack was found. From that information no one wanted to keep the system online.
RE: Monitoring a leak through pipe crack
Also well done for refusing to send anyone up they to fix it while it was live. That's always been one of my red lines. If I wasn't prepared to go and do it I wasn't going to send someone else.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Monitoring a leak through pipe crack
Also reading up on API 579, does that actually hold for through wall cracks ? As in how does a code deem a through wall crack to be acceptable ?
RE: Monitoring a leak through pipe crack
But do note that 579 isn't a code per se, it's a recommended practice.
Nathan Brink
RE: Monitoring a leak through pipe crack
RE: Monitoring a leak through pipe crack
Either something went totally wrong in the translation from Japanese to English or there are some very weird inspection techniques out there.
RE: Monitoring a leak through pipe crack
Apparently still done in many countries
https://en.wikipedia.org/wiki/Wheeltapper
http://www.railwayarchive.org.uk/stories/pages.php...
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Monitoring a leak through pipe crack
Can just picture this:
"Shane, how did your inspection of our 500 ton crane boom go - acceptable or not ? "
"Sounds good boss ! "
RE: Monitoring a leak through pipe crack
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Monitoring a leak through pipe crack
ultrasonic testing.