Pneumatic Double Offset High‑Performance Flanged Butterfly Valve is a high‑performance butterfly valve adopting double‑offset structure and driven by pneumatic actuator. Both ends of the valve body feature flanged connections, suitable for industrial pipeline systems requiring high sealing performance, fast open‑close efficiency and reliable operation.
Compared with conventional concentric butterfly valves, the double‑offset design creates two offsets of the disc rotational axis relative to the valve body centre and sealing centre. Upon valve opening, the disc lifts off the sealing surface rapidly to reduce friction and wear between the sealing ring and seat. During closing, the disc gradually compresses against the seat to form reliable sealing, achieving a good balance of low friction, long service life and superior sealing performance.
Working Principle of Pneumatic Double‑Offset Flanged Butterfly Valve:
Valve Opening Process: The pneumatic actuator drives the stem to rotate. The disc lifts off the seat immediately after rotating only a few degrees. Throughout the full 90‑degree travel, the disc remains separated from the seat for most of the stroke with almost no scraping or wear.
Valve Closing Process: The sealing face of the disc contacts the seat only when approaching the fully‑closed position. Sealing is realized by the wedging force generated from the offset geometry pressing the disc against the seat. Higher medium pressure brings stronger sealing compression force to achieve reliable bi‑directional shut‑off.
Pneumatic butterfly valves are widely used in industrial piping systems for fast, automatic and reliable flow isolation and regulation. Equipped with pneumatic actuators, these valves enable remote operation and can be integrated with PLC, DCS and automatic control systems for efficient process control. Key parameters including working temperature, medium, pressure rating, valve size, actuator type and connection standard should be confirmed before ordering to ensure proper valve selection. Customized valve sizes, pressure ratings, connection types, sealing materials, body materials and pneumatic actuator configurations are available for various industrial and non-standard applications. (Unit: mm)
| NPS | NPS | Type/Class | Part No | A | B | C | L | H | h | P | S | D | D1 | z-d | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 80 | 3″ | D642-150LB | D642P150XLX3 | 73 | 121 | 93 | 114 | 82 | 27 | 11.2 | 14.8 | 190 | 152.4 | 4-φ19 | |
| 100 | 4″ | D642-150LB | D642P150XLX4 | 96 | 133.3 | 110 | 127 | 82 | 27 | 11.2 | 14.8 | 230 | 190.5 | 8-φ19 | |
| 125 | 5″ | D642-150LB | D642P150XLX5 | 111 | 135 | 120 | 140 | 82 | 27 | 11.2 | 14.8 | 255 | 215.9 | 8-φ22 | |
| 150 | 6″ | D642-150LB | D642P150XLX6 | 142 | 152.4 | 143 | 140 | 82 | 27 | 14 | 18 | 280 | 241.3 | 8-φ22 | |
| 200 | 8″ | D642-150LB | D642P150XLX8 | 188 | 187.3 | 172 | 152 | 82 | 27 | 15.9 | 21.9 | 345 | 298.5 | 8-φ22 | |
| 250 | 10″ | D642-150LB | D642P150XLX10 | 236 | 231.8 | 202 | 168 | 97 | 28 | 20.6 | 28 | 405 | 362 | 12-φ26 | |
| 300 | 12″ | D642-150LB | D642P150XLX12 | 282 | 260.3 | 241.3 | 178 | 97 | 33 | 23.8 | 33.3 | 485 | 431.8 | 12-φ26 | |
| 350 | 14″ | D642-150LB | D642P150XLX14 | 314 | 315 | 295 | 190 | 105 | 41 | 28.7 | 37 | 535 | 476.3 | 12-φ29 |
Pneumatic high‑performance butterfly valves can be fitted with double‑acting or single‑acting pneumatic actuators. According to automation control requirements, accessories such as solenoid valves, limit switches, air filter‑regulators and valve positioners can be equipped to realize remote control, automatic on‑off operation and process modulation.
They are widely applied in oil & gas, petrochemical, chemical, power, metallurgy, water treatment, paper‑making, shipbuilding and industrial process control sectors, serving for shut‑off and control of air, natural gas, steam, water, oil products and various industrial media.
