Previous in Forum: Where Does "P.dV" Work in Brayton Combustion Stage Go?   Next in Forum: All Requirements for a Pressure Vessel Under ASME Sec 8 Div I
Close

Comments Format:






Change Mode
Close

Subscribe to Discussion:

CR4 allows you to "subscribe" to a discussion
so that you can be notified of new comments to
the discussion via email.

Close

Rating Vote:







Add Vote
6 comments
Rate Comments: Nested
ChemistUSX
Associate

Join Date: Nov 2012
Posts: 34

Buttefly Valve Material Seat - for Steam

05/13/2020 12:37 PM

Hi,

For butterfly valves used for steam I need to define the material seat for them. The steam used is at 1.6 barg 126°C, max 140°C

We currently have EPDM seats . It depends on the type of the EPDM i've read. normal EPDM resistance is 120°C. Some providers offers other kinds of EPDM to 150°C.

Is PTFE an option for steam at 140°C?

Thanks
Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Good Answers:

These comments received enough positive votes to make them "good answers".

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!
3
SolarEagle
Guru

Join Date: Mar 2007
Location: by the beach in Florida
Posts: 33392
Good Answers: 1817
#1

Re: Buttefly Valve Material Seat - for Steam

05/13/2020 3:38 PM

PTFE coated EPDM is probably your best bet...

"Rated for temperatures -20°F to 300°F. The Teflon liner overlays EPDM which is bonded to a rigid phenolic ring on the outside seat perimeter. The PTFE extends over the seat faces and outsides flange seal diameter, completely covering the EPDM elastomer layer of the seat, which provides the resilience for sealing valve stems and the closed disc."

https://www.triadprocess.com/butterfly-valve-seat-selection-guide/

http://www.flowlinevalves.com/assets/butterfly-valves/76-77-full-template.pdf

__________________
 All living things seek to control their own destiny....this is the purpose of life
Register to Reply Good Answer (Score 3)
Go to Next Good Answer
2
redfred
Guru
Engineering Fields - Electrical Engineering - Been there, done that. Engineering Fields - Control Engineering - New Member

Join Date: Dec 2008
Location: Long Island NY
Posts: 15600
Good Answers: 981
#2

Re: Buttefly Valve Material Seat - for Steam

05/13/2020 4:09 PM

I would be apprehensive to specify materials to use with this valve. Let the valve manufacturer offer you material options that meet your operating environment. You might find they have on the shelf a valve seat suitable for 200°C.

__________________
 "Don't disturb my circles." translation of Archimedes last words
Register to Reply Good Answer (Score 2)
No more Good Answers. Go to first "Almost" Good Answer
The Prof
Guru
Engineering Fields - Mechanical Engineering - New Member Hobbies - CNC - New Member

Join Date: Aug 2006
Location: Western Australia
Posts: 767
Good Answers: 58
#4
In reply to #2

Re: Buttefly Valve Material Seat - for Steam

05/14/2020 3:09 AM

Agree, let the valve manufacturer specify and you approve. Specify a tightness requirement and even specify soft seat.

I would only accept (as others heave said) PTFE, filled PTFE or UHMW Polyethylene (Ultra High Molecular Weight)

__________________
 If you can't explain it simply, you don't understand it well enough. (A.E.)
Register to Reply Score 1 for Good Answer
Go to Next "Almost" Good Answer
The Prof
Guru
Engineering Fields - Mechanical Engineering - New Member Hobbies - CNC - New Member

Join Date: Aug 2006
Location: Western Australia
Posts: 767
Good Answers: 58
#6
In reply to #4

Re: Buttefly Valve Material Seat - for Steam

05/15/2020 11:55 PM

I tried to edit my comment, but apparently failed.

If considering UHMW PE then it must be a special blend, the standard product will not be suitable for your temperatures.

__________________
 If you can't explain it simply, you don't understand it well enough. (A.E.)
Register to Reply
phoenix911
Guru
Hobbies - CNC - New Member Hobbies - DIY Welding - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Aug 2007
Posts: 23647
Good Answers: 420
#3

Re: Buttefly Valve Material Seat - for Steam

05/13/2020 6:17 PM

PTFE would be a better choice, thats rated for 300°F, (150°C).

__________________
 “ When people get what they want, they are often surprised when they get what they deserve " - James Wood
Register to Reply
PWSlack
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 32175
Good Answers: 839
#5

Re: Buttefly Valve Material Seat - for Steam

05/14/2020 3:26 AM

The steam conditions in the original post are not particularly arduous, and there will be several solutions."Polyfill", being PTFE impregnated with microscopic glass beads, is another option, for example.

The advice above of letting the valves distributor offer against a temperature, pressure and fluid description is the best way forward. It's all about warranty. If the Client specifies the <...Buttefly Valve Material Seat - for Steam...> and it turns out to be a mistake, then it's the Client's problem. If the valve distributor specifies it and it's a mistake, it's the valve distributor's problem. It's best to place the risk where the most expertise lays.

__________________
 "Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Register to Reply Score 1 for Good Answer
No more "Almost" Good Answers.
Register to Reply
Have a Different Question?
6 comments

Good Answers:

These comments received enough positive votes to make them "good answers".

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!
Copy to Clipboard

Users who posted comments:

phoenix911 (1); PWSlack (1); redfred (1); SolarEagle (1); The Prof (2)

Previous in Forum: Where Does "P.dV" Work in Brayton Combustion Stage Go?   Next in Forum: All Requirements for a Pressure Vessel Under ASME Sec 8 Div I

Advertisement

Got Something to Say?
Ask a Question
Start a Discussion

Search this Forum
Mechanical Engineering:
Go

CR4 Sections
Aerospace
BioMech & BioMed
Chemical & Material Science
Civil Engineering
Communications & Electronics
Education and Engineering Careers
Electrical Engineering
General Discussion
Instrumentation
Manufacturing
Mechanical Engineering
New Technologies & Research
Software & Programming
Sustainable Engineering
Transportation

Site Directories
Forum Directory
Blog Directory
User Group Directory
RSS Feeds

CR4 Rules of Conduct
CR4 FAQ
Site Glossary

Who's Online (205 right now)
Show Members
Advertisement