The D673H pneumatic triple-offset regulating butterfly valve is an industrial automation execution unit consisting of a high-performance pneumatic piston actuator and a triple-offset multi-level hard-seated butterfly valve body. By receiving standard 4-20mA DC analog signals from the control system, the electro-pneumatic positioner converts the signal into pneumatic power to drive the disc rotation within a 0-90 degree range. Its unique triple-offset design (shaft offset from flow center, shaft offset from seal center, and seal cone axis offset from flow axis) allows the disc to detach from the seat instantly upon opening, fundamentally eliminating mechanical friction and wear between sealing pairs. Featuring a metal hard-seal structure, this series offers high temperature/pressure resistance, erosion resistance, and tight shut-off, making it ideal for petroleum, chemical, power, and metallurgy industries where precise regulation and harsh conditions coexist.

Product Image of D673H Pneumatic Triple-Eccentric Control Butterfly Valve

1、The valve seat and disc sealing surfaces are treated through processes such as overlay welding with stainless steel, Stellite alloy, or hard material coating, forming a highhardness metal sealing pair. This design offers excellent wear and erosion resistance, with a service life significantly exceeding that of softsealed butterfly valves.

2、Multi Eccentric Design
Utilizing single eccentric, double eccentric, or tripleeccentric construction, the disc instantly separates from the seat during valve operation, achieving frictionfree opening and closing. This results in low operating torque and minimal wear on the sealing surfaces.

3、High Temperature and HighPressure Performance
The metal hard seal structure enables the valve to withstand higher operating temperatures (typically up to 425°C or above) and higher working pressures, making it suitable for hightemperature and highpressure media such as steam, thermal oil, and hot flue gas.

4、Pneumatic Rapid Control
Equipped with a highperformance pneumatic actuator (piston or vane type), the valve provides fast opening and closing speeds. It supports remote automatic control and integration with DCS/PLC systems to meet automated process control requirements.

5、Excellent Sealing Performance
Relying on the wedgelike compression effect generated by the eccentric design, the valve ensures tight contact of the metal sealing surfaces when closed. It offers reliable bidirectional sealing, with leakage levels reaching ANSI Class VI or higher standards.

6、Corrosion and Abrasion Resistance
The high hardness of the metal sealing surfaces, combined with the option of corrosionresistant alloy materials or surface hardening treatments for the valve body and key components, effectively resists medium corrosion and erosion from solid particles. Suitable for slurry or fluegas pipelines containing dust or particulate matter.

7、FireSafe Design
Selected models incorporate firesafe functionality. In the event of a fire, the metal sealing pair can maintain a certain degree of sealing performance even after any soft sealing materials are destroyed, preventing largescale media leakage. Complies with firesafety standards such as API 607.

8、Long Service Life and Low Maintenance
Thanks to minimal friction and high wear resistance, the valve delivers extended service life. Maintenance intervals are prolonged, allowing for longterm maintenancefree operation under normal conditions, significantly reducing overall lifecycle costs.

Structural Diagram of D673H Pneumatic Triple-Eccentric Control Butterfly Valve

Parts List and Materials Specification

Performance Specification Sheet

Standard requirements for external dimensions

1. The structural length of the valve shall comply with the standard of GB/T12221

2. Connecting flanges according to GB/T17241.6 standard

Outline Diagram of D673H Pneumatic Triple-Eccentric Control Butterfly Valve

Overall Dimension Table