Short time Vacuum after Check Valve

[rezaghaani]

I am going to use a check valve after my cylinder and before coming into my system,in some cases I need to evacuate my system to wash the residual air in the line. I am wondering whether is it necessary to put a bull valve after the check valve to protect it from the vacuum or the check valve will not have problem to have vacuum in one side for less than one second?

 

[bimr]

It would be a more reliable scheme to use a valve instead of a check valve. Check valves are not considered to be as reliable as a valve.

 

[pennpiper]

rezaghaani,
Could you please be more descriptive the system and the situation?
What is upstream and what is downstream?
What is the function of the piping and valves you included in your original post?



Sometimes its possible to do all the right things and still get bad results

 

[LittleInch]

The presence of a vacuum on one side of a check valve should not be an issue as it only raises the differential pressure by 1 bar max and unless your check valve has a very low pressure rating then it should be ok.

As noted above, single check valves are not normally considered to have good isolation properties, but may be sufficient for your needs.

Most check valves don't like sudden or violent flow reversal and can be damaged by repeated shock loading. Therefore it all depend on how the flow changes direction / stops and over what time scale.

Without more data (valve type, pressure rating, material etc) then it's not easy to say much more.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.