Concealed rod hard seal gate valve

1. Product Overview

Concealed Rod Hard Seal Gate Valve, internationally named Non-Rising Stem Metal Seated Gate Valve, is a widely used pipeline shut-off valve specially designed for buried, narrow and compact installation environments.

The valve body is cast from QT450 nodular cast iron with blue epoxy anti-corrosion coating, standard flanged connection, PN10/PN16/PN25 pressure classes. Different from rising stem gate valves, its operating stem only rotates without extending outward when opening or closing, greatly saving vertical installation space and avoiding stem corrosion, collision damage during underground burying. The metal hard sealing wedge realizes tight bidirectional shut-off, suitable for water supply, heating, sewage and industrial high-temperature medium pipelines.

2. Working Principle

When rotating the handwheel, the internal threaded sleeve converts rotary motion into vertical lifting of the wedge gate plate, while the valve stem itself only spins and keeps its height unchanged (concealed structure).

The wedge and valve body sealing surface are overlaid with hard alloy to form metal-to-metal hard seal, achieving zero leakage under high pressure. The concealed stem structure isolates the thread from external soil, water and air, effectively preventing rust and thread jamming for long-term underground service.

3. Core Features

Concealed Non-Rising Stem Design, Space-Saving & Buried-Friendly

Stem does not protrude when opening/closing, occupies less vertical space, perfectly fits underground buried pipelines, valve wells and narrow equipment rooms; prevents stem abrasion, bump damage and external corrosion.

Metal Hard Sealing, Wide Medium & Temperature Adaptation

Stellite alloy surfacing on sealing faces, metal hard seal withstands high pressure, high temperature and media with tiny solid particles, far more durable than soft rubber sealing valves.

Bidirectional Zero Leakage Performance

Precision machined wedge sealing pair, meets international pipeline tightness standards, no reverse medium leakage under rated working pressure.

Full Bore, Low Flow Resistance

Straight-through full internal bore when fully open, minimum fluid pressure loss, ideal for long-distance main transmission pipelines.

Long Service Life for Underground Installation

Internal stem thread is isolated from external corrosive media; overall epoxy anti-rust coating, suitable for long-term buried underground use without frequent maintenance.

Optional Locking Handwheel (Match Your Locking Valve Series)

Can be equipped with padlock locking device to prevent unauthorized misoperation, supporting municipal anti-theft pipeline management.

4. Typical Application Scenarios

Municipal buried tap water, sewage and rainwater pipe network

Urban heating hot water, steam heat supply pipelines

Community underground valve wells, narrow underground pipe trenches

Factory circulating water, high-temperature industrial fluid cut-off pipelines

Power plant, chemical plant medium transmission systems

Farmland underground buried irrigation main pipes