The A42Y-160/320 spring fully open closed high-pressure safety valve is suitable for equipment and pipelines with working temperatures ≤ 200 ℃ for media such as air, ammonia hydrogen mixture, etc. A42Y-160P/320P and A42Y-160R/320R spring fully open closed high-pressure safety valves are suitable for equipment and pipelines with corrosive media working at temperatures ≤ 200 ℃, as overpressure protection devices. The valve connecting flanges of the above models produced by Shanghai First Ring Road shall comply with the standard JB/t2769-92.