BS EN ISO 10434:2020

What is ISO 10434 about?

ISO 10434 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 can indicate a need for full port openings, heavy wall sections, and large stem diameters.

ISO 10434 sets forth the requirements for the following gate valve features:

• Bolted bonnet
• Outside screw and yoke
• Rising stems
• Non-rising handwheels
• Single or double gate
• Wedge or parallel seating
• Metallic seating surfaces
• Flanged or butt-welding ends

ISO 10434 covers valves of the nominal sizes DN:

• 25; 32; 40; 50; 65; 80; 100; 150; 200; 250; 300; 350; 400; 450; 500; 600

Corresponding to nominal pipe sizes NPS:

• 1; 1¼; 1½; 2; 2½; 3; 4; 6; 8; 10; 12; 14; 16; 18; 20; 24

ISO 10434 applies for pressure Class designations:

• 150; 300; 600; 900; 1 500; 2 500;

ISO 10434 also applies for pressure PN designations:

• 16, 25, 40, 63, 100, 160, 250 and 400

Who is ISO 10434 for?

ISO 10434 on bolted bonnet steel gate valves for the petroleum is beneficial for:

• Manufacturers of bolted bonnet steel gate valves
• Exporters of bolted bonnet steel gate valves

Why should you use ISO 10434?

Bolted bonnet valves are ideal for high-pressure steam, catalytic reformers, hydrocrackers, and other tough services.

ISO 10434 assists the user with body seats. Integral body seats are permitted in austenitic stainless-steel valves. When austenitic stainless steel or a hard-facing material is used for the body seat, this material may be weld deposited directly on the valve body. Body seating surfaces have an adequate seating area and do not have sharp corners at either the inner or outer seat circumference in order to prevent galling or damage to the wedge or disc when operated against full differential pressure. The purpose of ISO 10434 is to establish the basic requirements and practices for flanged and butt-welding end steel gate valves of bolted bonnet construction. When designing the stem, gland, lantern ring (if supplied), and backseat the manufacturer keeps into account stem guiding and the prevention of packing extrusion.

Overall, ISO 10434 is helpful as ISO 10434 provides body guides that are designed to minimize wear of the valve, to accurately position the gate throughout the travel into its seat, and to ensure the alignment of the gate and stem in all orientations without the gate binding or galling.

What’s changed since the last update?

BS EN ISO 10434:2020 supersedes BS EN ISO 10434:2004, which is withdrawn.

BS EN ISO 10434:2020 cancels and replaces the second edition (ISO 10434:2004), which has been technically revised.

The main changes compared to the previous edition are as follows:

• Normative references were updated
• Higher PN and Class designations have been added, including PN 63, 160, 250 and 400
• Design and manufacturing requirements for the stem to wedge connection have been added