Non-rising Stem Resilient Gate Valve

Non-rising Stem Resilient Gate Valve, commonly abbreviated as NRS resilient gate valve, is a mainstream soft-sealing cut-off valve specially designed for buried pipelines and narrow valve chambers. Its most distinctive feature is that the valve stem only rotates without upward extension when opening or closing, which saves vertical installation space greatly compared with rising stem gate valves. Equipped with an integrally rubber-coated wedge gate, this valve realizes bubble-tight zero leakage shutoff and is widely used in all kinds of water delivery pipeline systems. It can only be used for fully open or fully closed fluid isolation and is not suitable for flow regulation.

Working Principle

Turn the handwheel to drive the internal screw thread to push the wedge gate to move vertically up and down. The stem is concealed inside the bonnet and will not stretch out externally regardless of opening degree. When the valve is fully closed, the elastic rubber layer vulcanized on the gate tightly presses against the sealing surface of the valve body under medium pressure, forming a flexible soft seal to completely cut off fluid flow. When fully open, the gate retracts to the upper cavity, forming a straight-through full bore channel with minimal flow resistance and no dead space for sediment accumulation. EPDM packing at the top of the bonnet effectively stops medium leakage along the stem, and built-in guide ribs keep the gate moving vertically without deviation to ensure smooth operation.

Core Advantages

Concealed non-rising stem design occupies little vertical space, perfectly matching underground buried installation and compact valve well layout.

Full resilient rubber wedge achieves reliable tight sealing without dripping or seepage, complying with drinking water health standards.

Straight-through full bore structure reduces pipeline flow resistance, lowers pump energy consumption and prevents sludge deposition inside the valve cavity.

Ductile iron valve body with internal and external fusion bonded epoxy coating delivers superior anti-rust and anti-corrosion performance for long-term underground service.

Simple internal structure with few vulnerable components, easy to disassemble, inspect and maintain on site without professional tools.

Clear opening-closing indicator installed on the bonnet top, which directly reflects the valve working state for convenient operation management.

Flexible installation mode, supporting horizontal and vertical mounting to adapt to various pipeline construction conditions.

Main Material Configuration

The valve body and bonnet are cast from high-toughness ductile iron with uniform epoxy powder coating on both inner and outer surfaces to resist soil corrosion and medium erosion. The wedge gate uses ductile iron as base material, fully covered with food-grade EPDM elastic rubber through vulcanization process, featuring high elasticity, wear resistance and anti-aging performance. The valve stem is made of stainless steel to avoid rust and abrasion during frequent switching. EPDM rubber packing is adopted for stem sealing, and all connecting bolts and nuts are stainless steel to prevent rust locking after years of burial.

Technical Parameters

Nominal diameter covers DN50 to DN1200 to satisfy different pipeline flow requirements. Standard pressure grades are PN10 and PN16, and PN25 high-pressure specification can be customized according to customer demands. Flange connection follows international universal standards for quick matching with standard pipe fittings. Applicable medium temperature ranges from -10℃ to 70℃. Applicable media include municipal tap water, domestic sewage, agricultural irrigation water, industrial circulating neutral water and fire-fighting water. Each finished valve undergoes strict shell strength test and sealing hydraulic test before factory delivery to guarantee stable and reliable performance.

Application Scope

This non-rising stem resilient gate valve is the preferred cut-off equipment for urban buried water supply pipe networks, municipal drainage pipelines, farmland irrigation projects, pump station supporting pipelines, water treatment plants, residential building water supply and fire-fighting pipeline systems. It is widely applied in underground buried projects and small-size valve chambers for pipeline isolation and routine maintenance.