This International Standard specifies the requirements for bolted bonnet steel gate valves having the following features: - bolted bonnet; - outside screw and yoke; - inside screw (alternative for PN IO, PN 16, PN 20, PN 25 and PN 40 only); - Single or double obturator; - wedge or parallel seating; - with or without non-metallic obturator or seat Seals; - flanged or butt-welding ends. lt covers valves of the nominal sizes DN 10; 15; 20; 25; 32; 40; 50; 65; 80; 100; 125; 150; 200; 250; 300; 350; 400; 450; 500; 600; 700; 800; 900; 1 000, and applies to valves of the nominal pressures PN 10; 16; 20; 25; 40; 50; 100.