Stainless Steel Telescopic Metal-sealed butterfly Valves

The Stainless Steel SD343H Telescopic Metal-sealed Butterfly Valve is a medium-to-large-sized pipeline control valve integrating a triple-offset structure, metal hard-seal, axial telescopic compensation, and worm gear drive. The entire valve body is fabricated from stainless steel materials (304/316/304L/316L/2205 duplex stainless steel, etc.), making it suitable for high-temperature, high-pressure, and highly corrosive medium environments.

Driven by a worm gear mechanism to rotate the valve stem, the valve drives the disc to complete opening, closing, or regulating actions, achieving reliable shut-off and flow control of media. The valve body integrates a built-in telescopic compensation structure, which can absorb axial displacement caused by temperature differences in pipelines without the need for additional expansion joints, effectively reducing the risk of system stress concentration.

With its stable structural design and reliable metal-sealing performance, the Stainless Steel Telescopic Metal-sealed Butterfly Valves is commonly used in industrial pipeline systems with complex working conditions, frequent temperature variations, or long pipeline lengths.

Structure & Working Principle Description

1. Triple-offset Structure Design

The valve adopts the proven triple-offset butterfly valve structure of the SD343 series. Through triple offset design, the disc can quickly disengage from the valve seat at the initial opening stage and achieve linear compression only at the final closing phase, delivering the following benefits:

● Low friction during opening and closing

● Minimal wear on the sealing surface

● Stable opening/closing torque and long service life

This structure is particularly suitable for metal hard-seal applications, maintaining reliable sealing performance even under high-temperature and high-pressure conditions.

2. Metal Hard-seal System

Both the valve seat and disc sealing surfaces are precision-machined and ground from metal materials, available in two options: stainless steel body seal or stellite 6 overlay welding structure. It features:

● Resistance to high temperatures and pressure shocks

● Excellent erosion and wear resistance against particle-laden media

● Suitability for frequent opening and closing operations

The metal hard-seal design ensures the valve maintains stable sealing performance in high-temperature steam, flue gas, and particle-containing media. 

3. Telescopic Compensation Structure

The valve is equipped with a built-in axial telescopic mechanism that can freely expand and contract within a certain range to compensate for displacement caused by thermal expansion and contraction of pipelines: 

● Expansion/contraction range varies with nominal diameter

● Effectively reduces flange connection stress

● Enhances overall system safety

This design is especially critical for heating pipe networks, long-distance transmission pipelines, and systems with significant temperature fluctuations.

4. Worm Gear Drive Mechanism

The valve comes standard with a worm gear drive unit, paired with a handwheel for operation, offering the following characteristics:

● Large transmission ratio for effortless opening and closing

● Supports precise flow regulation

● Superior self-locking performance for stable operation

In large-diameter or high-pressure applications, worm gear drive can effectively reduce operational load and improve on-site operational safety.

Key Product Features

● All-stainless steel structure for stable corrosion resistance

● Triple-offset design ensures low opening/closing torque and minimal wear

● Metal hard-seal suits high-temperature and high-pressure media

● Built-in telescopic compensation function of the valve body reduces pipeline stress

● Flange connection enables convenient installation and maintenance

● Worm gear drive delivers smooth and reliable operation

The Stainless Steel Telescopic Metal-sealed Butterfly Valves balances sealing reliability and structural stability under complex working conditions, making it ideal for long-term continuous operation systems.

Typical Applications

Technical Parameters

Material Configuration Description

Selection & Usage Recommendations

When selecting the Stainless Steel Telescopic Metal-sealed Butterfly Valves, focus on the following key factors:

1.Medium Characteristics: Choose the corresponding stainless steel and sealing materials based on medium corrosivity and particle content.

2.Pressure & Temperature: Match the design pressure and reserve adequate safety margins.

3.Pipeline Displacement: Ensure the valve’s telescopic compensation range exceeds the actual axial displacement of the pipeline.

4.Flange Standards: Verify consistency with on-site pipeline flange standards.

5.Operation Method: For large-diameter or high-pressure applications, prioritize worm gear mechanisms with high transmission ratios.

Summary

By integrating sealing performance, displacement compensation, and operational stability into a single valve unit, this product series reduces the number of system accessories and improves the overall reliability of pipeline systems.

In industrial scenarios involving medium-high pressure, high temperatures, and significant pipeline displacement, the Stainless Steel Telescopic Metal-sealed Butterfly Valves maintains stable long-term operation, lowers maintenance frequency, and is well-suited for long-term use and large-scale deployment in engineering projects.