Product Overview
OS&Y (Outside Stem and Yoke) flanged gate valve UL Listed and FM Approved for fire protection. Rising stem design provides positive visual indication of open/closed position critical for NFPA 20 fire pump installations.
Certifications
- UL Listed (UL 508)
- FM Approved (FM 1120/1130)
- NFPA 13 / NFPA 20 Compliant
- SABER Compliant (Saudi Arabia)
- Civil Defence Approved (UAE)
Technical Specifications
| Type | Flanged Gate Valve - OS&Y Pattern |
| Standard | API 600, ASME B16.34, NFPA 20 |
| Size Range | 2" - 24" (DN50 - DN600) |
| Pressure Rating | Class 150 / 300 (PN20/PN50) |
| Connection | ASME B16.5 Raised Face Flanges |
| Body Material | Cast Iron / Ductile Iron / Carbon Steel |
| Bonnet Material | Cast Iron / Carbon Steel (Bolted Bonnet) |
| Gate/Wedge Material | Cast Iron with Bronze Trim / SS316 Overlay |
| Stem Material | Silicon Brass / SS316 (Rising Stem) |
| Seat Material | Metallic (Integral or welded) |
| Operator | Handwheel / Chain Wheel / Gear Operator |
| Temperature Range | -10 deg C to +250 deg C (depending on rating) |
Key Features
- UL Listed and FM Approved per FM 1120
- OS&Y (Outside Stem and Yoke) design for position visibility
- Straight-through full bore minimizes pressure loss
- Flexible-wedge gate design for uniform seating
- Bolted bonnet construction for maintenance access
- Bronze/SS trim for water service compatibility
- Non-rising stem option available for space constraints
- Chain wheel operator for underground pit service
Applications
Frequently Asked Questions
Why are gate valves required for fire pump installations?
NFPA 20 (Standard for the Installation of Stationary Pumps for Fire Protection) mandates gate valves at specific locations in fire pump piping: discharge isolation, suction isolation, and circulation relief. Gate valves are specified because they provide minimal restriction to flow (straight-through full bore) and clear open/closed position indication via the rising stem. The OS&Y (Outside Stem and Yoke) design exposes the stem thread to maintenance inspection and prevents bonnet leakage from going undetected in critical fire pump applications.
What is the difference between OS&Y and inside stem gate valves?
OS&Y (Outside Stem and Yoke) gate valves have the stem thread external to the bonnet, providing visible stem movement that indicates valve position without disassembly. Inside stem gate valves have the stem thread within the valve body, offering a more compact profile but hiding the stem condition from inspection. For fire protection per NFPA 20, OS&Y valves are preferred and often required because maintenance personnel can verify stem condition and lubrication without removing the bonnet from a pressurized system.
What flange standards apply to fire protection gate valves?
Fire protection flanged gate valves in North American specifications use ASME B16.1 (Class 125 cast iron), ASME B16.5 (Class 150/300 steel), or AWWA C515 (ductile iron) flange standards. The flange facing is typically Raised Face (RF) with smooth or serrated finish. For Middle Eastern exports conforming to FM approval, the valves must meet both the ASME dimensional standards and FM Global's performance requirements for fire pump installations.
What materials are specified for fire protection gate valve internals?
Internals (wedge, seat, stem) use bronze or brass alloys for corrosion resistance in water service. Common trim designations per API 600: Bronze trim (ZQ/ZU), 13% Chromium SS (CK3/CK5), or 316 SS (SS316). For fire protection, the standard trim is silicon brass (D-2 or E-2) providing excellent galvanic compatibility with water and resistance to dezincification. Supreme Valves provides material traceability certificates with all fire protection valves per FM and NFPA documentation requirements.
Ready to Order?
Contact our export team for pricing, Production schedules, and technical support for your fire protection project.
Email: supremevalvesindia@gmail.com | We export to Saudi Arabia, UAE, Qatar, Kuwait, Oman, Bahrain
Purchase Options
Materials of Construction (MOC)
| Component | Material Specification |
|---|---|
| Body & Bonnet | Ductile Iron (ASTM A536 / EN-GJS-400-15) |
| Stem / Spindle | SS 410 / SS 420 |
| Seat / Trim | EPDM / NBR / Bronze |
Technical Specifications
| Parameter | Specification / Standard |
|---|---|
| Manufacturing / Design Standard | EN 1171 / AWWA C509 / BS 5163 |
| Testing Standard | API 598 / EN 12266-1 |
| Pressure Rating | PN16 / PN25 |