Dust Cap Only For A417A Vapor Relief Valve

For installation in the vapor area of Anhydrous Ammonia containers. Their function is to open and relieve the pressure when it exceeds the designed working pressure of the container. They permit a gradual opening to relieve moderately excessive pressure and accelerate to full discharge capacity when pressure increases beyond the allowable set pressure.

All Vapor Relief Valves are permanently marked with their identifying catalog number, date of manufacture, *removal date, set pressure, and flow capacity. All ammonia tanks should have provision for vapor relief valves with adequate capacity to meet discharge requirements. These valves meet ASME standards.

* Removal date is 5-years from date of manufacture. Set at 250 PSI (ST A1310B at 265 PSI).