high pressure steam article

John S.

found an interesting read and wanted to share:
<a href="http://www.kirsner.org/kce/media/pdfs/KirsnerHammer.pdf">KirsnerHammer.pdf</a>

<A HREF="http://www.heatinghelp.com/getListed.cfm?id=366&Step=30">To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"</A>

Kevinj_3

Steam

As a contractor we work with steam up to about 125 psi on a regular basis and operate a few high pressure plants for our customers. I have used this article to help drive home the dangers of trapped condensate to our people. They look stunned every time I show them what can happen. It is easy to get careless with steam and many people don't realize that heating the trapped water will cause rapid expansion and devestation.

Tony Conner_2

Actually...

...it's the collapse of a steam bubble in subcooled condensate that really causes the problem. The resulting pressure spike from the water rushing into a near perfect vacuum is spectacular.

Kirsner's site is excellent - he has several articles posted, along with a waterhammer quiz, and some impressive photos of the resulting damage. www.kirsner.org

Gene_3

I was almost

killed once, well, the ground moved and I ran real fast.

We were warming up a line at a facility, I was at the middle station, another down the street and one up on a hill, we had our line warm, the guy on the hill, well, he didn't want to work late so instead of opening his bypass and bleeding off the condensate he opened the 20" main.

We figure about 300 gallons of water shot down to us, our lines went dead, the water pushed the steam back to the guy down from me, then as it settled it came back towards me with the steam behind it.

My pit starting making weird hissing noises and I could hear the balls inside the pair of 2" traps rattling violently, then came about a dozen violent explosions that lifted me a couple of inches off the ground as I ran.

It cracked open the cast iron cases of the 2" traps and crushed the balls, the valves were destroyed and all welded joints were busted as well. If I remember it was about $50,000 worth of damage.

After about 2 days the adrenaline subsided and I was ok.

The guy that opened the valve????

They promoted him, I kid you not.

Dale

Good story

When I read that a few years ago I made a list of the easy things they could have done, like taking the traps apart to confirm they could drain water and weren't blocked, and as a guy posted here I think from Alaska, open the valves a quarter turn per hour so all that underground iron has plenty of time to warm up slowly and give the traps time to drain.

Gene_3

yep

we used to plan it to take a day or 2, slower the better and safer, it is really amazing how flexible large steel pipe is, I've seen about 100 yrds of above ground pipe flex like a snake, you have to shake your head and say " did I really just see what I think I saw???".

Kevinj

Tony

Thanks for spelling it out better, I need to work on my writing skills !!!!