Danfoss NRVS 25 stainless-steel check valve, OEM P/N 020-2033. A compact non-return valve designed to be mounted inside an EVRA solenoid valve or PM main valve to prevent reverse refrigerant flow. Unlike the NRVA, the NRVS has no damping feature. Stainless-steel valve housing; applicable to HCFC, HFC and R717 (ammonia). Port 1 in. Max working pressure 28 bar (406 psig); media temperature -50 °C to 140 °C. minimum opening differential pressure 0.11 bar. Flammable hydrocarbons are not recommended.