H61, H64 (Y, H) - PN 100, 160, 200, 250, 320P54, P55, P57-100V, 140V, 170V high-temperature and high-pressure welded check valves are suitable for cutting and connecting pipeline media on various systems of petroleum, chemical, thermal power plants, and hydraulic systems with nominal pressures of PN1.6~32.0MPa and P54/100V-P57/170V, working temperatures of 540C (including 170V working temperature of 570). Applicable media include water, steam, and oil.