Pneumatic Double Offset High‑Performance Lug Butterfly Valve is a high‑performance butterfly valve with double‑offset structure, lug‑type body and pneumatic actuator drive. Independent lugs are provided on both sides of the valve body for bolting connection with pipeline flanges. It features firm installation, convenient disassembly and assembly, and suitability for pipe end mounting.
The double‑offset structure creates two offsets of the stem axis relative to the disc centre and sealing centre. Upon valve opening, the disc lifts off the seat rapidly to reduce friction and wear between sealing surfaces. During closing, the disc gradually compresses against the seat to achieve reliable sealing. Therefore, compared with conventional concentric butterfly valves, this design delivers low operating torque, superior sealing performance, minimal wear and extended service life.
Working Principle of Pneumatic Double‑Offset High‑Performance Lug Butterfly Valve:
Valve Opening Process: The pneumatic actuator drives the stem to rotate. The disc lifts fully off the seat quickly after rotating only a few degrees. Throughout the full 90‑degree operating travel, the disc stays completely separated from the seat for most of the stroke, free from scraping, friction and abrasion. It effectively protects the sealing surfaces and greatly extends valve service life.
Valve Closing Process: The sealing face of the disc comes into contact with the seat only when approaching the fully‑closed position. The mechanical wedging force generated by the double‑offset structure compresses the disc firmly against the seat. Higher medium pressure produces stronger wedging force for self‑reinforced sealing performance, achieving stable and reliable bi‑directional bubble‑tight 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 | J | K | M | F | K | N-W |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 65 | 2.5″ | TD672-150LB | TD672P150XLX2.5 | 59 | 111.1 | 82.5 | 48 | 82 | 27 | 11.2 | 14.8 | 125.4 | 22.4 | M10 | 180 | 139.7 | 4-5/8″-11UNC |
| 80 | 3″ | TD672-150LB | TD672P150XLX3 | 73 | 120.5 | 93 | 48 | 82 | 27 | 11.2 | 14.8 | 125.4 | 22.4 | M10 | 190 | 152.4 | 4-5/8″-11UNC |
| 100 | 4″ | TD672-150LB | TD672P150XLX4 | 96 | 133.3 | 110 | 54 | 82 | 27 | 11.2 | 14.8 | 125.4 | 22.4 | M10 | 230 | 190.5 | 8-5/8″-11UNC |
| 125 | 5″ | TD672-150LB | TD672P150XLX5 | 111 | 135 | 120 | 57 | 82 | 27 | 11.2 | 14.8 | 125.4 | 22.4 | M10 | 255 | 215.9 | 8-3/4″-10UNC |
| 150 | 6″ | TD672-150LB | TD672P150XLX6 | 142 | 152.4 | 135 | 57 | 82 | 27 | 14 | 18 | 125.4 | 22.4 | M10 | 280 | 241.3 | 8-3/4″-10UNC |
| 200 | 8″ | TD672-150LB | TD672P150XLX8 | 188 | 187.3 | 172 | 64 | 82 | 27 | 15.9 | 21.9 | 125.4 | 22.4 | M10 | 345 | 298.5 | 8-3/4″-10UNC |
| 250 | 10″ | TD672-150LB | TD672P150XLX10 | 236 | 231.8 | 202 | 71 | 97 | 28 | 20.6 | 28 | 142.7 | 37.3 | M12 | 405 | 362 | 12-7/8″-9UNC |
| 300 | 12″ | TD672-150LB | TD672P150XLX12 | 282 | 260.3 | 241.3 | 81 | 97 | 33 | 23.8 | 33.3 | 142.7 | 37.3 | M12 | 485 | 431.8 | 12-7/8″-9UNC |
| 350 | 14″ | TD672-150LB | TD672P150XLX14 | 314 | 315 | 295 | 92 | 105 | 41 | 28.7 | 37 | 142.7 | 37.3 | M16 | 535 | 476.3 | 12-1″-8UN |
The pneumatic lug‑type high‑performance butterfly valve is driven by a pneumatic actuator. It can be configured with double‑acting or single‑acting actuators and fitted with accessories such as solenoid valves, limit switches, air filter‑regulators and valve positioners to achieve remote automatic control. It is widely suitable for oil & gas, petrochemical, chemical, power, metallurgy, water treatment, paper‑making, shipbuilding and industrial automation systems.