Safety valve on a sil-air 15 export compressor
by John Hudson
(Oldham, United Kingdom)
Hi Bill, I've just bought a Sil-AIr 15A export and I need to replace the safety valve. In the manual it says BAR-6 87 PSI. Could you please tell me which is the correct safety valve to use with this model. The original has a 1/4 inch thread. Do I buy one 10% over the cut-out, or is the bar-6 the cut out level plus 10%?
John, your model of Sil-Air has a maximum pressure output of 6 Bar or approximately 90 PSI.
That is not the setting of the PRV however.
The pressure relief valve's purpose is to vent over pressured air should the compressor not shut off at the normal cut out, in your compressor case, that would be 6 bar.
I do not know what the factory setting for the pressure relieve valve on the Sil-Air is. It were me, and this were my compressor, I'd acquire a PRV with a pressure release set point about 1 Bar or 15 PSI above the normal cut out.
I did a quick check and found sources for a PRV that was set to release at 8 bar. If this were my air compressor I would be OK with a PRV set to 8 bar if the normal cut out was 6 bar.