Gate Valve Selection Guide: Resilient vs. Solid Wedge, OS&Y vs. NRS
Gate valves are isolation valves: they're built to be fully open or fully closed, giving an unobstructed full-bore flow path with very low pressure drop. They are not made for throttling — a partially open gate vibrates and erodes. Here's how to choose one.
When to use a gate valve
Pick a gate valve for infrequent on/off isolation where you want full flow and minimal pressure drop — mains, pump isolation, and shutoff duty. For frequent operation or throttling, choose a butterfly valve or a ball valve instead.
Wedge type: resilient vs. solid
| Wedge | How it seals | Best for |
|---|---|---|
| Resilient (resilient-seated) | Rubber-encapsulated wedge seals on a smooth body — no bottom groove to collect debris | Water & wastewater mains, the modern standard (AWWA C509/C515) |
| Solid / metal wedge | Metal-to-metal seat | Higher temperature/pressure and industrial process service |
Stem type: OS&Y vs. NRS
OS&Y (Outside Screw & Yoke / rising stem): the stem rises as the valve opens, giving a clear visual open/closed indication — common in fire protection and above-ground industrial lines. NRS (Non-Rising Stem): the stem doesn't travel up, so it fits tight spaces and buried/below-grade service (operated by a nut and key).
Standards
Resilient-wedge water gate valves are built to AWWA C509 (full-body) or C515 (reduced-wall, lighter); industrial gate valves often follow API 600. Iron-body flange drilling follows ASME B16.1 Class 125. See flanged gate valve dimensions for lay-length notes.
Material
Match the body to your service — see the body material guide. Ductile iron is standard for water; stainless or carbon steel for chemical or high-temp service.
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Browse gate valves or contact us with your line size, pressure, and service for a recommendation.