Threaded Metal Seated Gate Valve

1. Product Overview

Threaded metal seated gate valve, also known as screwed hard seal gate valve, is a small-bore shut-off valve designed with internal thread connection and metal-to-metal hard sealing pairs.

Different from flanged gate valves, it adopts NPT/BSP internal thread ends for quick installation on small-diameter pipelines without flanges or welding. The sealing surface is overlaid with Stellite hard alloy, which solves the aging and leakage problems of soft rubber seals under high temperature, high pressure and abrasive working conditions. It is widely used for small branch pipelines that require tight cut-off and convenient disassembly.

2. Working Principle

Rotate the handwheel to drive the valve stem to lift or lower the solid wedge gate vertically.

Fully open: The gate completely leaves the flow passage, bringing minimum flow resistance to the medium.

Fully closed: The metal wedge fits tightly against the metal valve seat to achieve zero leakage shut-off.

This valve is only suitable for full open or full closed cut-off, not for flow throttling service.

3. Core Features

Hard Seal Performance

Metal hard sealing surface with Stellite alloy surfacing, high hardness, wear-resistant and anti-scratch.

Wide temperature range: -20℃ ~ 425℃, suitable for high-temperature steam, hot oil and heat transfer medium.

Excellent erosion resistance, applicable to media with tiny particles, ash and impurities.

Self-sealing wedge structure: Higher medium pressure brings tighter sealing effect.

Threaded Connection Advantage

Standard NPT / BSPP / BSPT internal thread ends, simple installation, no welding required.

Compact overall structure, small volume, light weight, ideal for narrow installation spaces.

Easy disassembly for maintenance, convenient to replace the whole valve without cutting pipelines.

Structure Design

Valve body materials: WCB carbon steel, SS304, SS316 stainless steel optional.

Polished anti-corrosion valve stem, low operation torque, smooth opening and closing.

Straight-through full flow channel, no dead zone to accumulate sediment.

External screw & yoke (OS&Y) design, intuitively judge valve opening position by stem extension.

High-temperature graphite packing, stable sealing of stem, no medium leakage.

4. Main Technical Parameters

Nominal Diameter: DN15 ~ DN50 (1/2" ~ 2")

Pressure Rating: PN16, PN25, PN40; Class150, Class300

Connection Type: Internal thread (NPT / BSP)

Sealing Type: Metal hard seal (Stellite 6 overlay)

Operation Mode: Manual handwheel

Working Temperature: -20℃ ~ 425℃

Applicable Media: Steam, compressed air, water, oil, gas, weak acid and alkali fluid, particle-containing industrial medium

5. Application Scope

Small-branch pipelines of heating equipment, boiler auxiliary systems

Petrochemical small-diameter process pipelines

Steam pipelines in machinery manufacturing and textile factories

Water, gas and oil supply branch pipes of municipal engineering

Small equipment supporting pipelines with high temperature and pressure requirements

6. Product Highlights

Threaded connection realizes fast mounting and removal, saving construction cost and time.

Metal hard seal avoids soft seal aging failure, greatly extending service life under harsh working conditions.

Compact size adapts to limited installation space such as equipment cabinets and narrow pipe trenches.

Multiple material options for valve body to match different corrosive media.

Strict hydrostatic and air leakage test before delivery, stable zero leakage performance.