high pressure rating soft seated ball valve

[anand25111987]

Hi,

Can we use elastomers seats for valves which are high pressure rated ( for 1500 rated and above). I am under the impression that these elastomer's mechanical properties will not allow it to withstand these high pressure(240 bar for 1500 rating considering a case) . Shouldn't we use only metal seated for this 1500 rated to have a long life cycle of the valve.

P.S: I am new to this valve Industry and your comments will helpful

 

[gerhardl]

As always size, form and exposure to fluid type and mechanical pressure, temperature, flow, abrasion, cavitation (if any) and other application details will decide what is sensible to use. Size and form of valve seat (2m or 2mm?) will of course matter.

But yes, for instance PEEK may be used as a seat elastomere sealing at theese pressures if other parameters are suitable.

 

[anand25111987]

Hi gerhardl - Thanks for your response.
Is there are any international standards or global customer specifications which limits the usage of soft seat relating it to the pressure rating.

 

[gerhardl]

This is a question impossible to answer, as there is an almost unlimited number of 'customers', constructions and regulations. General rules tend to be more scarse for higher pressures, and most regulations tend to focus on metallic material constructional details for presuure containing parts, or parts that must withstand mechanical forces. There is (generally, in my opinion, not so much focus on sealing material selection.

Functional tests for higher pressures for valves focus on short-time tests for sealing leakages. As elastomeres might develop leakages or drawn out deformations giving leakages over time and under certain circumstances at higher pressures, elastomers will not always be suitable for selection.

 

[anand25111987]

Thank you for your response.

 

[mbelly84]

elastomers seats are not suitable for pressure classes 900 & higher. they will extrude in short time.

there is no need to go metal-to-metal
go with a high strength thermoplastic material like DEVLON-V or PEEK

obviously i am supposing your fluid is clean