High Temperature Ball Valve Seat with DEPG (Selexol)
High Temperature Ball Valve Seat with DEPG (Selexol)
(OP)
Hey Everyone,
I have about 30 6"-12" ball valves through which DEPG/Selexol (dimethyl ethers of polyethylene glycol) passes. We currently use teflon seats but a few of the valves have started leaking (process, not externally). The highest temperature these valves see is 250 F. Any suggestions on a valve seat material or kits?
Thanks,
Heather
I have about 30 6"-12" ball valves through which DEPG/Selexol (dimethyl ethers of polyethylene glycol) passes. We currently use teflon seats but a few of the valves have started leaking (process, not externally). The highest temperature these valves see is 250 F. Any suggestions on a valve seat material or kits?
Thanks,
Heather





RE: High Temperature Ball Valve Seat with DEPG (Selexol)
What pressure are you dealing with? Problematic medium (abrasive/corrosive/other)? And how long have these valves been on the line and what is the diagnostic of the reason why some valves are leaking and others not?
Corrosion resistant, exotic alloy valves from The Alloy Valve Stockist in Barcelona, Spain http://www.gate-valves.com
RE: High Temperature Ball Valve Seat with DEPG (Selexol)
RE: High Temperature Ball Valve Seat with DEPG (Selexol)
Hsbcn: I agree!
In addition: History? How long in operation before leaks? Possibillity of crack-openings(99,9% ???) giving cavitation or drawing of sealing material? Check of position, adjustment of limit and torque switches if any. Slack and precision and adjustment of any mechanical connection and operator. Best tip: to replace one of the worst valves including operator, and inspect directly, valve inside included, this will tell you a lot. Pictures of damage?
PTFE should in itself be OK, as far as I can see, both for fluid and temperature. However, as there is a multitude of PTFE fillers and other details of fabrication details giving again a multitude of 'PTFE's', there could be an unfortunate mismatch for this particular PTFE's fabrication or application.
RE: High Temperature Ball Valve Seat with DEPG (Selexol)
250 F doesn't need anything other than reinforced Teflon. Unreinforced PTFE creeps too easily to use in a big valve like these.
RE: High Temperature Ball Valve Seat with DEPG (Selexol)