We were recently asked what cracking pressures are available with our SVC/SHC springless sanitary check valves and if they are designed for gases.
Well, yes they are, they’re designed for both gases and liquid applications. The cracking pressures are listed in our data sheet. For the polymer disk, that’s the Teflon or PEEK disk, the cracking pressure is 2.76 millibar or about 0.4 psid.
For the316 solid disk or the 316 disk with the EPDM soft seal, the cracking pressures are 8.96 millibar or about 0.13 psid. Note, that we don’t list a cracking pressure for the polypropylene disk. It actually would be about the same as the polymer disk but we don’t list it because that particular disk is only used in liquid down-flow applications. So that disk is open at all times and the only time it will close is if the water raises in the drain causing the buoyant disc to rise into the seat and close off.
So as long as you have a water based liquid for the SVC down flow application, you will be fine.