OS&Y vs NRS Gate Valve
Rising stem OS&Y versus non-rising stem NRS gate valves — headroom, indication, buried service. Supreme Valves India guide.
Quick take
Many fire specifications prefer OS&Y for visual stem indication. Confirm listing and stem type on the RFQ. See the gate valve hub and UL/FM fire valve RFQ for listed constructions.
When to choose each option
Use the RFQ checklist on linked landing pages to lock MOC, class, ends, and listing requirements before commercial evaluation. Wrong material or stem type is a common cause of rework on site.
- Match medium, temperature, and chloride level first.
- Confirm flange standard (ASME Class vs PN) and face type.
- State fire-safe, cryogenic, or listing needs explicitly.
- Send the full BOQ line — size mix drives price and lead time.