Pneumatic Cryogenic Triple‑Offset Flanged Butterfly Valve‑Extended Stem

Pneumatic Cryogenic Triple Offset Flanged Butterfly Valve is a high‑performance metal‑seated butterfly valve specially designed for low‑temperature and cryogenic applications. It features triple‑offset geometry, flanged end connections and pneumatic actuator drive.

The triple‑offset sealing design enables nearly friction‑free or low‑friction movement between the disc and seat during opening and closing. This effectively reduces wear on sealing surfaces, improves sealing performance and extends service life.

To meet cryogenic service requirements, the valve is generally fitted with an extended bonnet / extended stem structure. This keeps the actuator and packing area away from cryogenic media, preventing packing freezing and minimizing cold‑loss.

Operating Principle of Pneumatic Cryogenic Triple‑Offset Flanged Butterfly Valve with Extended Stem：
Opening Stroke: Compressed air enters the pneumatic actuator and generates rotational torque to turn the valve stem. Thanks to the cam‑effect of triple‑offset geometry, the disc lifts away from the seat sealing surface at the initial opening stage without rubbing. The disc rotates to a position parallel to the pipeline flow‑path, and the valve is fully open for unobstructed cryogenic media flow.

Closing Stroke: Upon receiving control signals, the actuator rotates in reverse to drive the disc. Only at the final closing stage, the conical sealing face of the disc presses tightly against the metal seat to form reliable metal‑to‑metal sealing and shut off cryogenic media.

Automatic Control: Fitted with solenoid valves, limit switches or positioners, the valve performs automatic on‑off and flow regulation responding to PLC/DCS signals. Spring‑return single‑acting or double‑acting pneumatic actuators are available to meet safety requirements for cryogenic service.