Wedge Gate Valve (Flanged / Threaded, OS&Y vs. NRS)

Dependable Linear Isolation for High-Capacity Fluid Infrastructure

In mechanical plant rooms, water distribution networks, and fire suppression mains, operators require an absolute method to isolate specific pipe zones for maintenance, repairs, or system extensions. Unlike throttle-style valves, a Gate Valve is designed strictly for fully open or fully closed linear operation. Because the internal wedge retracts entirely out of the flow path when opened, it provides a straight-through, "full-bore" clearing that eliminates severe fluid turbulence and pressure drops across the valve body.

Our gate valves are precision-engineered to withstand continuous hydrostatic loads and severe water hammer stresses. The valve relies on a threaded stem connected to a handwheel, which drives a heavy wedge vertically into the valve seat. When spun clockwise, the wedge wedges firmly into place, forming a robust mechanical seal against high downstream pressures.

Core Valve Architectures

To accommodate varied installation locations and monitoring regulations, gate valves are built in two primary design configurations:

1. Outside Screw and Yoke (OS&Y) / Rising Stem

• Instant Visual Tracking: The threaded stem rises out of the handwheel assembly as the valve opens. This allows facility operators and safety inspectors to immediately verify from a distance whether the line is open or closed.

• Protected Threads: Operating threads stay entirely outside the fluid path, shielding them from internal scaling, chemical corrosion, and mineral buildup.

• Best For: Fire protection sprinkler mains, main plant room loops, and pump discharge lines.

2. Non-Rising Stem (NRS)

• Space-Constrained Design: The internal stem rotates in place to draw the wedge up or down, meaning the valve maintains a fixed height whether fully open or closed.

• Best For: Tight vertical clearances, buried underground water mains, and compact valve pit enclosures.

Key Performance Features

• Resilient-Seated Technology: The internal wedge is encapsulated in high-durability EPDM or NBR rubber, compressing cleanly against the smooth, epoxy-coated valve body to eliminate the debris traps common in old metal-seated designs.

• Fusion-Bonded Epoxy (FBE) Armor: Fully lined and coated with an electrostatically applied, non-toxic fusion-bonded epoxy layer, maximizing corrosion protection against harsh chemicals and aggressive soils.

• Full-Bore Hydrodynamics: The interior flow track mirrors the pipe’s exact nominal diameter, lowering pump energy costs by reducing internal friction.

• Triple-O-Ring Stem Sealing: Outfitted with a premium multi-layered O-ring packing gland structure that prevents external weeping and allows maintenance seals to be replaced while the line remains under full working pressure.

• Robust Traffic-Ready Castings: Poured from high-tensile Ductile Iron ($ASTM\ A536$), providing superior structural yield strengths compared to traditional gray cast iron.

Ideal Infrastructure Applications

• Municipal Water Distribution Networks: Serving as underground isolation checkpoints for neighborhood main grids and reservoir transfer hubs.

• NFPA-Compliant Fire Pump Rooms: Deployed as primary suction and discharge isolation valves on main electric or diesel fire pump lines.

• HVAC Chillers & Large Commercial Plumbing: Providing reliable sectional isolations across large corporate office heating and cooling loops.

Technical Performance MatrixEngineering MetricFlanged Resilient Gate ValveThreaded Utility Gate ValveNominal Diameter RangeDN50 ($2"$) up to DN600 ($24"$) standard$1/2"\text{ (15 mm)}$ up to $2"\text{ (50 mm)}$Stem Architecture BlueprintOS&Y (Rising Stem) or NRS OptionsNon-Rising Stem (NRS) ProfileEnd Connection InterfaceFlanged (ANSI Class 150 / PN16 / PN10)Female Threaded (NPT / BSP)Maximum Working Pressure16 bar ($232\text{ PSI}$) to 25 bar ($362\text{ PSI}$)16 bar ($232\text{ PSI}$) ContinuousFactory Shell Test PressureHydrostatic validation up to 1.5$\times$ WorkingHydrostatic validation up to 1.5$\times$ WorkingWedge & Seating CompoundEPDM / NBR Rubber Encapsulated WedgeSolid Brass / Bronze Tapered WedgeBody Shell MetallurgyDuctile Iron (ASTM A536 Grade 65-45-12)Cast Brass (C37700) / Forged BronzeStandard Procurement Package Components

• Complete Gate Valve Assembly with Handwheel (or Direct-Drive Operating Nut)

• Forged Stainless Steel Stem and Internal Wedge Components

• Technical Pressure Rating Certification and Alignment Sheet

• Optional System Add-ons: Pre-wired Electrical Tamper Switches (for OS&Y models), Flange Gasket Bolt Kits, and T-Wrench Extension Spindles for Buried NRS Vaults (Sold Separately)