Parr stocks the poppet check valves for incorporation into the user’s supply lines. These valves are typically constructed of T316SS with FKM O-rings with a 10 psi cracking pressure. Alternate O-ring materials and cracking pressures are available upon request.
Whenever gases or liquids are introduced into a vessel under pressure, the supply pressure must be greater than the pressure in the vessel to prevent reverse flow back into the supply system. Protection against reverse flow can be obtained by installing a check valve in the supply line. With a check valve in the line, the valve will snap shut if the supply pressure is lower than the pressure in the vessel. This protection is particularly important on stirred reactors where gas enters through a dip tube. With liquids in the vessel, any back pressure will force liquid back into the gas tank or into the gas supply system.