Swing type check valve in steam service?
Can I use swing type check valve in steam service (600#, 900# and 1500#)?, if so, what would be the criteria selection of this type of valves in steam service?. Is it safe to use and install swing type check valves in steam lines?.
Swing type checks can be used in steam, however they are usually
considered the 'lower end' when it comes to longevity and reliability.
Two things for this service: NO soft seats, metal to metal only, and you cannot install with flow down in a vertical pipe.
The biggest problem with check valves generally, in any service, is that they routinely get WAY oversized for the flow conditions. This results in the disks flapping up and down like flags in the wind. This causes greater pressure drop than a correctly sized (smaller) valve that gets driven open, and stays fully open. The other problem with oversizing is premature wear at the shaft that holds the disk in place.
Check out Hy-Grade valves. These guys make a valve that is at the upper end of check valves.
TBP
is right but if you chec out the HyGrade design they have an integral
flapper and pin. Really only 4 parts to the valve. It works like a
champ.
They have a double seated design so they can get tight shutoff
in metal to metal. You cannot however ignore the proper piping
practices with any check valve inline or you will get unfavorable
results. Make sure you have the required pipe diameters before and
after the valve.
And I would suggest that dual plate wafer check valves are worth considering for Steam applications.
These are much lighter than traditional swing check valves and have better response times.
For steam service normally the seat faces are hard faced (Stellite).
The two major manufacturers of this type of valve are Stockham (Crane) and Goodwin International.
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