Thermal Shut-off Valves

Thermal Shut-off Valves are heat-insulated globe valves specially designed for media that tend to solidify, crystallize, or require constant-temperature transportation.They feature an all-stainless-steel main body and an integrated thermal insulation jacket structure. The valve controls flow and regulates flow rate by raising and lowering the disc via the valve stem.

Steam, hot water or other heating media can be circulated in the jacket area, or rock wool, glass wool and other insulation materials can be filled inside, to stabilize the medium temperature, prevent solidification and crystallization at low temperature, excessive heat dissipation at high temperature, and reduce system energy consumption.

Thermal Shut-off Valves are fully made of stainless steel, with reinforced sealing design for both the jacket and main valve. They feature excellent corrosion resistance, high temperature resistance and reliable sealing, and are manufactured in strict accordance with relevant national and American standards.They are widely used in petrochemical, food processing, pharmaceutical, heating, coal chemical and other industries, serving as key valves for stable delivery of crude oil, syrup, asphalt, chemical slurry and other media.

Core Structure & Features

Main Structure

● Body, bonnet and insulation jacket are integrally formed in stainless steel.

● Straight-through flow passage with low flow resistance for smooth medium delivery.

● Outside Screw & Yoke (OS&Y) structure for clear open/close indication and easy maintenance.

Insulation Structure

● Jacket type: steam/hot water circulation for high precision temperature control.

● Filled type: rock wool, glass wool or polyurethane filling for easy installation.

Sealing Structure

● Metal hard seal: hard alloy hardfacing, suitable for high temperature and wear-resistant service.

● PTFE soft seal: excellent tightness, suitable for low temperature and clean media.

Actuation

Manual, electric and pneumatic actuation are available to meet on-site operation and remote automatic control requirements.

Main Technical Parameters

Basic Specifications

Connection & Actuation

● Connection: Flanged (RF, MFM)

● Flange Standard: GB/T 9113, ANSI/ASME B16.5

● Actuation: Manual (handwheel), Electric (multi-turn, explosion-proof), Pneumatic (double/single acting)

Sealing & Testing

Component Materials

Design & Manufacturing Standards

● Valve Design: GB/T 12235, API 602, ASME B16.34

● Face-to-Face: GB/T 12221

● Flange Dimensions: GB/T 9113, ANSI/ASME B16.5

● Pressure-Temperature Rating: GB/T 12224

● Thermal Insulation: GB/T 4272, HG/T 20570

● Material Standards: GB/T 1220, ASTM A182

● Installation: GB 50235, ASME B31.3

Selection Guidelines

Insulation Type by Medium

● Temperature > 100℃: jacket type with steam/hot water circulation

● Low temperature < 0℃ or easy to solidify at room temperature: filled insulation

Material by Corrosiveness

● General medium: 304 stainless steel

● Chlorine, acid or strong corrosion: 316L stainless steel

Seal by Temperature

200℃ high temperature: metal hard seal

● Low temperature / clean medium: PTFE soft seal

Actuation by Application

● Small bore, manual operation: handwheel

● Remote control & automation: electric/pneumatic actuator

Jacket Pressure

Steam jacket pressure ≤ 1.6 MPa to avoid seal damage.

Installation, Operation & Maintenance

Before Installation

Check model, pressure, material and insulation type. Clean impurities inside the body, flanges and jacket ports.

During Installation

Install in correct flow direction (low inlet, high outlet). Ensure jacket ports are properly oriented. Tighten flange bolts diagonally and evenly to prevent jacket deformation.

Before Startup

Perform hydro/pneumatic test on the jacket to ensure no leakage before introducing heating medium. Preheat or precool the line medium to avoid sudden temperature change.

Operation & Maintenance

Regularly inspect jacket sealing, insulation effect and stem packing. Shut down for repair in case of leakage.Descale circulation jackets periodically. Check aging of filled insulation and replace if necessary.

Restart After Long-term Storage

Check stem movement manually. Reinspect jacket and insulation structure before putting into service.