Defines the requirements for a series of compact steel gate, globe and check valves for petroleum and natural gas industry applications. It is applicable to valves of nominal sizes (DN) 8, 10, 15, 20, 25, 32, 40, 50, 65, 80 and 100, to corresponding nominal sizes, to nominal pipe sizes (NPS) of a quarter, three eighths, half, three quarters, one, one and a quarter, one and a half, two, two and a half, three and four, and to pressure designation classes 150, 300, 600, 800 and 1500.