Expansion joints and Anchors for steam distribution. 1

[onuigbo]

I need to establish a standard for expansion joints and Anchors for steam distribution application, for pressures up to 250 psi. Currently, we use HYSPAN slip-type expansion joints, I don't want bellows for this application. I need as much opinion as possible, with the relative merits of HYSPAN and other joint manufacturers.

I always like to seize the advantage of your valued experience.

We deliver steam as if your life depends on it.

 

[rmw]

Have you done a site search of eng-tips, yet? There is information on what you are asking already contained in several threads.

rmw

 

[SellAmeco]

Another manufacturer of slip-type expansion joints is Advanced Thermal Systems (ATS). It is my opinion that the ATS exp.joint is superior to Hyspan in its construction. ATS uses a dual plating process on the slip to minimize or eliminate any scratches on the slip. Also, they use a non-metallic guide ring to eliminate scoring on the slip surface. You can check out more information on ATS on their website:

http://www.advancedthermal.net.

You are correct in not wanting bellows joints for steam systems: it's not a matter of if the bellows will fail, but WHEN.

 

[Thomasjl]

No bellows in my piping systems, only piping expansion loops! Only use bellows in the ultimate case that you don't have room for expansion bellows. If you can avoid bellows, avoid it.

 

[timbones]

I agree with Thomasjl, all the steam plants I have ever worked on use expansion loops, not bellows. Corners and changes in elevation provide great natural locations to allow for pipe expansion.

I was at a power plant in Texas last year that had about 2 miles of 30" 800 F steam piping to a neighbouring steam host. Looked like an inch worm creaping across a field with all the vertical expansion loops.

 

[friartuck]

I agree. Natural expansion is best and cheapest....also nothing much to go wrong.

I use a company called engineering appliances in the uk who believe it or not try to solve your expansion problems without selling you an expansion bellows. Sounds like negative selling but it works quite well..you also know that the solution they come up with is professional and justified rather than just to increase their profit margin.

they have a web site also.

good luck

ps there is also some good info in CIBSE guide book B (brown guide) which shows you how to allow for natural expansion with hints on guiding and bracketting the pipework etc.

Friar Tuck of Sherwood

 

[TBP]

If onuigbo is dealing with a university/hospital campus steam system, or a downtown urban area district heating operation with lines either direct-buried with manholes, or everything in tunnels, there will simply be no room for expansion loops. It will be bellows or slip-style expansion joints, and that's that. I spent a lot of time down a lot of steam manholes, and I NEVER liked seeing bellows joints down there. And I never met anyone who had to routinely enter manholes who did.

 

[DSB123]

Thomasjl,
There's a contradiction in your reply."Only use bellows in the ultimate case that you don't have room for expansion bellows". But I know what you meant to say "Only use bellows in the ultimate case that you don't have room for expansion LOOPs."

Agree with all of the posts. We have around 28km of steam pipe on our site which was installed from anywhere up to 50 years ago. Lines range from 20"nb to 43"nb. In the past the designers have used "GunPakt" joints (Slip-joints), Axial bellows and in some case lateral bellows to accommodate the expansion. All give problems with failures. The only systems that we do not have many problems with are those utilising expansion loops.