Signal hard seal gate valve

1.Product Overview

Signal hard seal gate valve,also called metal-seated signal gate valve,integrates metal hard sealing structure and built-in signal feedback device.It is a full shut-off valve specially designed for high temperature,high pressure,particle-containing medium and fire protection,industrial pipeline monitoring systems.

Different from ordinary hard seal gate valves,this model is equipped with an electric signal transmitter on the top stem.It can remotely output on-off status signals to fire control cabinets,DCS and PLC systems,realizing real-time remote monitoring of valve opening/closing state,which greatly improves pipeline safety management.

The sealing pair adopts metal-to-metal hard seal(Stellite alloy surfacing,stainless steel hard facing),solving the aging and failure defects of soft seal rubber under high temperature and abrasive working conditions,featuring long service life and stable zero leakage performance.

2.Working Principle

On-off Control Principle

Rotate the handwheel to drive the valve stem to lift or lower the wedge gate vertically.When fully open,the gate completely withdraws from the flow channel with minimal fluid resistance;when fully closed,the metal wedge tightly fits the metal seat to cut off medium flow thoroughly.This valve is only for full open/full close cut-off,not suitable for flow throttling.

Signal Feedback Principle

A precision travel switch sensor is installed on the signal box linked with the valve stem travel.When the valve reaches full open or full closed position,the mechanical trigger touches the switch,outputting passive electrical switch signals to the control room.Operators can instantly judge the actual valve state remotely without on-site inspection.

3.Core Structural&Performance Features

Hard Seal Advantages

Metal-to-metal sealing surface with hard alloy surfacing,resistant to high temperature(-20℃~450℃),high pressure(PN10~PN160/Class150~2500).

Excellent wear&erosion resistance,applicable to media with sediment,metal particles,ash and viscous fluid.

Anti-corrosion sealing surface,compatible with steam,hot oil,acid&alkali corrosive medium.

Self-tightening wedge design:higher pipeline pressure brings tighter sealing,stable low leakage rate.

Unique Signal Function

Independent signal feedback mechanism,IP65 waterproof signal box,suitable for outdoor&buried pipeline installation.

Dual signal output:full-open signal+full-close signal,supporting DC24V/AC220V power supply,matched with fire alarm and industrial automatic control system.

Mechanical linkage without electronic delay,accurate signal trigger,no misjudgment caused by medium pressure fluctuation.

Manual on-site observation window on signal cover for local status check when power fails.

Overall Structural Strength

Valve body material:ductile iron,WCB carbon steel,stainless steel SS304/SS316 optional;inner wall epoxy anti-rust coating for water&fire pipelines.

Stainless steel quenched valve stem,anti-rust,low operation torque,smooth switching.

Flat bottom full flow channel,no sediment accumulation,avoiding sealing surface scratch and blockage.

Modular split design,easy disassembly,on-site replacement of sealing parts without removing the whole valve from pipeline.

Flanged/grooved/welded connection available,easy to install on new and reconstructed pipelines.

4.Main Technical Specifications

Nominal Diameter:DN50~DN1200

Pressure Grade:PN10,PN16,PN25,PN40,PN64;Class150,Class300,Class600

Working Temperature:-20℃~450℃

Sealing Form:Metal hard seal(Stellite 6 surfacing)

Signal Type:Passive contact switch signal,double limit(open/close)

Signal Protection Grade:IP65

Operation Mode:Manual handwheel,worm gear,electric actuator

Connection End:Flange,grooved,butt weld

Applicable Medium:Fire-fighting water,high-temperature steam,petroleum,natural gas,sewage,chemical corrosive liquid,powder-containing industrial medium

5.Wide Application Fields

Fire protection engineering:Fire main pipeline signal cut-off valve,mandatory for fire linkage control systems.

Thermal power plant:High-temperature steam pipeline,boiler auxiliary water supply system.

Petroleum&chemical industry:Oil&gas transmission,corrosive medium cutting-off pipelines.

Metallurgy&mining:Slurry,ash water,particle-containing medium pipeline shut-off.

Municipal engineering:High-temperature heating network,industrial water supply&drainage.

Energy storage&chemical plant:Automatic pipeline interlock monitoring system.

6.Product Advantages Summary

Dual functions of pipeline shut-off+remote signal monitoring,one valve realizes two core requirements.

Metal hard seal structure overcomes high temperature and abrasive medium failure,far longer service life than soft seal signal valves.

Accurate signal feedback,compatible with mainstream fire control and industrial PLC systems,simple wiring.

Strong environmental adaptability,stable performance under high temperature,high pressure,outdoor buried and corrosive conditions.

Low maintenance cost,wear-resistant sealing surface,easy partial replacement of vulnerable parts.

Strictly tested per ISO,GB,FM fire protection standards,90%pressure and leakage inspection before delivery.