ISO 10434:2004 specifies the requirements for a heavy-duty series of bolted bonnet steel gate valves for petroleum refinery and related applications where corrosion, erosion and other service conditions would indicate a need for full port openings, heavy wall sections and large stem diameters. It sets forth the requirements for the following gate valve features: bolted bonnet; outside screw and yoke; rising stems; nonrising handwheels; single or double gate; wedge or parallel seating; metallic seating surfaces; flanged or butt-welding ends. It covers valves of the nominal sizes DN 25, 32, 40, 50, 65, 80, 100, 150, 200, 250, 300, 350, 400, 450, 500 and 600, corresponding to nominal pipe sizes NPS 1, 1 1/4, 1 1/2, 2, 2 1/2, 3, 4, 6, 8, 10, 12, 14, 16, 18, 20 and 24. It is applicable to pressure Class designations 150, 300, 600, 900, 1500 and 2500.