Welding of Valve to Valve

banerj1s ...As I said I've only used these type valves a few times, once in a 600# hydrocarbon service as a block valve. And once in a 600# feedwater line. Essentially they are a globe valve with the stem disconnected from the gate/piston ...so I would suspect they could be used anywhere a globe valve could be used. Now I'm guessing at this point there are 2 issues, for your use. You require a "quick acting" check valve. A piston check valve is a "non-slam" type check valve so I'm not sure this "check valve" will be suitable in the "quick acting" role(maybe JOP could wade in with his infinite wisdom on this?). The other issue would be a stop check valve is alittle on the "odd-ball" side, so trying to locate one for your application "could" be difficult and costly ...but again I'm not sure one this. HOWEVER for your initial problem this would be a GREAT fix! My $0.02 anyway. Good Luck my Friend!

Line size is 10" Design Temperature is 820 deg F and it is 300# class spec carbon steel. It is actually very much relevant to the intent of the original question because in case of a stop check valve the condition wont arise of a stop valve and a piston assisted check valve being placed together.
Thanks for the information Jop. Please can you confirm if you have used stop check valves on steam systems also?

Hi Friends can you help me who to calculate pipe sizing ,branch sizing and what are the charactors that we have to consider [/b]

Now there's one more issue I need to list here about this "stop check valve". IF you came upon this valve "cold turkey"(not knowing anything about it) you'd be hard pressed to know it was a check valve! First look you’d swear it was just a globe valve. Now this particular issue may or may not be a problem for you and your company, and the way around it would be to have good documentation and a particular symbol for a stop check valve. This doesn't always happen in my neck of the woods. So your people will need that information for any future interaction.
Here's a link for a "Petro" stop check valve that could probably cover your need, you'll have to verify that. Again Good luck!

www.petrovalve.com/products_type ... k%20Valves

Honey ...They are called "Engineers", normally a pain in the kester, but for that application they do a good job! *G* ...Everybody have a GOOD DAY! ...Mark