Rising Stem Resilient Seated Gate Valve

The Rising Stem Resilient Seated Gate Valve, also commonly referred to as OS&Y (Outside Screw and Yoke) resilient gate valve, is a high-performance ductile iron shut-off valve specially designed for municipal water supply, fire protection systems, water treatment plants, industrial plumbing and above-ground pipeline systems. Featuring a visible rising stem structure and EPDM resilient wedge sealing technology, this valve provides reliable bubble-tight zero leakage and intuitive working status indication, making it one of the most widely used fluid control valves for clean water and potable water pipeline projects worldwide.

Different from non-rising stem gate valves, the rising stem design is the core advantage of this series. The valve stem threads are fully exposed outside the valve yoke. During opening and closing operations, the stem moves vertically up and down with the gate wedge. Operators can directly observe the lifting height of the stem to accurately judge the valve’s fully open, fully closed or intermediate state without professional detection equipment. This visual position indication greatly improves on-site operation safety and daily maintenance efficiency, which is why rising stem resilient gate valves are mandatory and preferred for fire protection pipelines, pump stations and equipment rooms that require real-time status monitoring.

The valve body and bonnet are manufactured from high-strength ductile iron with excellent mechanical toughness, pressure resistance and anti-deformation performance. Both internal and external surfaces are coated with food-grade fusion-bonded epoxy powder. The smooth, non-toxic coating complies with drinking water standards and provides strong long-term anti-corrosion protection against oxidation, water immersion and environmental erosion. The full-bore flat-bottom cavity eliminates dead zones inside the valve, effectively preventing sludge and sediment accumulation, minimizing flow resistance and ensuring stable, low-loss fluid transportation when fully open.

This valve adopts an integrally vulcanized EPDM rubber resilient wedge as the sealing core. The entire gate disc is fully encapsulated with high-elasticity rubber material, achieving bidirectional tight sealing and zero leakage under rated pressure. The elastic rubber structure can automatically compensate minor sealing surface wear, thread clearance and micro pipeline deformation caused by long-term operation. Even if the water medium contains fine suspended particles, the resilient wedge can still maintain perfect fitting and tight shut-off performance, which is far superior to traditional metal-sealed gate valves that are prone to leakage and abrasion damage.

The valve stem is made of high-quality stainless steel with precision rolled threads, ensuring smooth lifting movement and low operating torque. Multi-layer waterproof and wear-resistant packing is equipped at the stem sealing position to effectively prevent medium penetration and external leakage. The built-in blowout-proof stem structure provides excellent safety protection under sudden pipeline pressure fluctuations, avoiding stem popping out and medium spraying risks.

Available pressure ratings include PN10 and PN16, with complete diameter specifications covering DN40 to DN1000. Flange dimensions comply with international GB, DIN and ISO standards, ensuring high compatibility with global standard pipeline systems. Multiple operation modes are optional, including manual handwheel, bevel gear drive and electric actuator, enabling automatic remote control and intelligent pipeline management for large-scale water supply projects.

It is strictly prohibited to use the valve for flow throttling purposes. The valve must only work under fully open or fully closed conditions. Long-term partial opening will cause high-speed water scouring, cavitation and vibration, which will damage the rubber wedge and reduce sealing lifespan. All finished valves undergo strict shell hydrostatic testing and seat tightness testing according to ISO 5208 standards before delivery to ensure stable quality and reliable field performance.

With intuitive stem position display, zero-leakage resilient sealing, low flow resistance, strong anti-corrosion ability and easy maintenance, the Rising Stem Resilient Seated Gate Valve has become a standard choice for fire safety systems, municipal waterworks, industrial water supply and commercial building plumbing projects. It delivers stable, safe and durable shut-off solutions for global water pipeline systems.