Non-Rising Stem Gate Valve (NRS)

A Non-Rising Stem Gate Valve is a gate valve in which the stem rotates without moving vertically outside the valve. The internal mechanism moves the gate between the open and closed positions. This design keeps the valve's overall operating height compact.

A rising stem gate valve moves the stem upward and downward as the valve operates. In an NRS gate valve, the stem rotates in place while the gate moves internally. As a result, NRS valves generally require less vertical clearance.

NRS gate valves are commonly used in underground water pipelines, municipal water systems, wastewater systems, valve chambers and installations with limited vertical space.

Yes. The compact operating height makes NRS gate valves well suited to underground and chamber installations. The complete valve configuration, coating, operating extension and installation arrangement should be selected according to the project requirements.

No. The stem does not rise externally. It rotates in place while the gate moves inside the valve.

Yes, depending on the valve construction and size. Pneumatic, electric and motorized operating arrangements can be supplied when suitable for the valve design.

Yes. Stainless steel options can include CF8, CF8M, CF3, CF3M, SS304, SS316 and SS316L, subject to size and design.

Yes. Ductile iron NRS gate valves are widely used for water and utility applications. Epoxy-coated configurations can also be supplied where required by the service or project specification.

Yes. Resilient-seated NRS gate valves can be supplied for suitable water, wastewater and utility applications.

Yes. Metal-seated configurations are available for applications where the specified pressure, temperature, media and service conditions require a metal seating arrangement.

Depending on the valve type and application, applicable standards can include API 600, API 602, ASME B16.34, AWWA standards, ASME B16.10, ASME B16.5, EN 558, EN 1092-1, API 598, ISO 5208 and EN 12266-1. The exact standard should be specified according to the valve design and application.

Yes. Extension arrangements can be supplied for underground valves and other installations where the operating point needs to be brought to an accessible location.

Gate valves are primarily intended for full-open or full-closed isolation service. Using a gate valve for continuous throttling can cause undesirable flow conditions and accelerated wear.

Selection should consider nominal size, pressure class, fluid, temperature, body and trim materials, seat design, end connection, installation environment, operating frequency and actuation requirements. For underground or space-constrained installations, the operating arrangement and extension requirements should also be defined.

Yes. Custom configurations can be considered for materials, pressure ratings, dimensions, end connections, coatings, trims, operation methods, actuators and inspection documentation according to the applicable project specification.