material selection for pneumatic valve

[nazrolf]

I have designed and built a pneumatic valve (current quantity four) with a G2 cast iron body and spool made of S7(Rc 50) with a lapped 45* seat and a land width of .125". It is used to control a circuit handling 250 psi for a valve gated hot runner.

Is this a good material selection for the body and spool?

I am considering using Dura-Bar 65-45-12 Ductile Iron
in replacement of the G2 for ease of manufacture but am concerned with the life of the seat.

Any suggestions?

 

[randi]

Your vlave material choice is dependent upon the process fluid, where it is to be used. That should have been the primary criteria along with other design factors, not an after-thought.

Various pneumatic valve types, sizes as well as material selection guides are available from a number of instrumentation suppliers like Invensys, Honeywell, Rosemount etc.

 

[atad]

Generally pneumatic valves are manufactured either from stainless steel or an Aluminium or Zinc/Aluminium Alloy.