Avoiding steam leaks--How to take care of it in Design phase itself? 1

[cjabhijit]

Dear All,

I have been recently visited a plant site for some revamp project information & saw steam leaking everywhere like at utility stations, steam traps etc. Most of the cases it was passing valves....

Steam leaks have multiple negative effects on steam-based plant operations, including energy losses, increased emissions, loss of reliability, production issues, and safety. Steam leakage is a major energy loss and we accept it as normal, but is it really normal?

You can also save tons of CO2 by changing steam systems to reduce leaks. Steam will erode and the leak will increase, which means you need to be very proactive in stopping it.

What can we do at design stage to avoid steam leaks to the extent possible?

Thanks & Regards,
Abhijit

 

[MFJewell]

Design a plant that is simple to operate and maintain.

 

[MJCronin]

Abhijit....

To minimize "steam leaks" in the piping design phase:

- Minimize flanged joints
- Seal weld all threaded piping joints

Have a responsible maintenance department with money and personnel assigned to:

- Stop and repair valves with steam stem or through leakage.
- Monitor repair and/or replace defective steam traps (this is a very simple thing to accomplish)
- Periodically blow down dirt legs



MJCronin
Sr. Process Engineer

 

[LittleInch]

buy better valves and minimize the number of them.

Weld as much as you can instead of screw joints

Make repair and isolation easy for the maintenance crews.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[lilliput1]

Protect control valves and traps with upstream strainer with blow off valve. Provide shutoff valve at steam and condensate branches to allow shutoff and repair of downstream valves, traps and equipment. Make sure there is good water treatment and steam boiler top and bottom blowdown system. Repair leaking valves and steam traps.

 

[cjabhijit]

Thanks for your inputs...

Considering that Valves are a prime source of steam leaks, & the primary reason valves leak is because they are purchased based on price rather than the leak rate.
Even a brand new valve will leak if it is not suited for the application.

What kind of valves are making the difference here? Is there a choice? In which ways?

Also, I think we should completely avoid threaded connections in steam service as these are prone to leakages.



Thanks & Regards,
Abhijit

 

[MJCronin]

http://www.plantservices.com/articles/2014/steam-leakage-tips/

MJCronin
Sr. Process Engineer

 

[mk3223]

The leak of the steam piping in operation can be a complicated issue resulted from the design, budget, material, fabrication, installation, inspection, operation, or routine maintenance.
It's a frustrated reality.

 

[rusty_sim]

- Minimise threaded fittings
- Use single body/piece valves

I think there's a bit of a trade-off between leak possibility and maintainability

 

[cjabhijit]

Thanks to all of you for your inputs.

MJCronin, basically it is all started with my recent field trip the article you are referring to below...

http://www.plantservices.com/articles/2014/steam-leakage-tips/

However, as I am mostly working on the Engineering part of it, I am really keen on the what kind of valves are making the difference here? Is there a choice? In which ways this can overcome?
If the Valve class & the cost is the issue how Client can insist on the correct class & not the obvious one due reduced cost by a contractor?

As per the same article, "A Class 1 valve leaks like a river. Class 6 valves have the tightest shutoff,”. Then what holds us to go with Class 1 or is it overdoing / overspending for the steam service?



Thanks & Regards,
Abhijit

 

[A8yssUK]

Hi Abhijit, could I also direct you to the European Sealing Association (ESA) they have a great range of documents about sealing systems done in partnership with the Fluid Sealing Association (FSA). Covering static and dynamic seals and how to get the best out of them.

https://europeansealing.com/en/publications

I am with you a great deal of easy savings can be done on plants by sealing better and more efficiently. I fail to understand why plant designers spend millions on equipment and then try to locate the cheapest possible connections they can find. Seals are by the very definition the weakest links in the pressure chain.. much safer places to be saving money IMHO.