Abstract ISO 15761 specifies 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. It includes provisions for a wide range of valve characteristics and is applicable to valve end flanges in accordance with ASME B16.5 and valve body ends having tapered pipe threads to ISO 7-1 or ASME B1.20.1.