Pneumatic Cryogenic Welded End Butterfly Valve ‑196℃ for Cryogenic Pipeline Systems

Pneumatic Cryogenic Welded Butterfly Valve is an automatically‑controlled butterfly valve specially designed for cryogenic medium piping systems. It adopts welded‑end connection to be directly welded to pipelines, featuring compact structure, reliable connection, stable sealing performance and suitability for harsh low‑temperature service conditions.

The valve is normally equipped with an extended stem / extended bonnet structure. This keeps the stem packing and pneumatic actuator away from the cryogenic medium zone, minimizing cold transfer to upper components, and mitigating frost formation as well as adverse impacts of low temperature on sealing performance and actuator operation.

Operating Principle of Pneumatic Cryogenic Butterfly Valve：
Opening Stroke: Upon receiving an opening signal from the control system, compressed air enters the pneumatic actuator to rotate the valve stem, which drives the concentric disc. The disc gradually moves away from the seat sealing surface, and the pipeline flow‑through area increases progressively. When the disc rotates parallel to the flow path, the valve is fully open, allowing smooth passage of cryogenic media. The metal‑to‑metal seal maintains good operating performance even under ultra‑low‑temperature conditions.

Closing Stroke: When the control system sends a closing signal, the pneumatic actuator operates in reverse and rotates the disc back to the closed position. The disc presses tightly against the metal seat sealing surface. Sealing is achieved by sealing specific pressure between metal contact faces to block the flow of liquefied media. The metal hard‑seated design resists ultra‑low temperatures and prevents seal‑component brittleness failure.

Automatic Control: Double‑acting or spring‑return single‑acting pneumatic actuators are optional. Solenoid valves control the air supply for remote valve on‑off operation; limit switches provide full‑open and full‑closed position feedback. Equipped with a valve positioner, the disc opening can be adjusted for continuous flow regulation. An extended stem design is adopted to isolate cryogenic cold transfer and protect the pneumatic actuator from low‑temperature damage.