I. Basic Product Definition
Electric ultra-low temperature fully welded extended stem ball valve is a special dedicated shut-off valve for cryogenic storage & transportation pipelines of LNG, liquid oxygen, liquid nitrogen and liquid hydrocarbons. It features an integrated three-in-one construction consisting of a monolithic fully welded valve body, custom extended valve stem and electric actuator, designed for working media as low as -196℃. It serves as the standard cut-off valve for insulated pipelines in cryochemical and liquefied energy industries.
The core function of the extended stem is to separate the thermal insulation layer and isolate the stuffing box from cryogenic fluid, preventing low-temperature frost damage to packing seals and actuator jamming caused by frozen valve stems. The fully welded body eliminates the risk of external leakage through the valve body itself. Since 2009, J-VALVES has focused on the R&D of fully welded extended stem ball valves, emerging as one of China’s pioneering original manufacturers to realize mass production of -196℃ cryogenic electric ball valves.
II. Core Construction & Key Technical Specifications
Valve Body: Integral Forged Fully Welded Body
J-VALVES valve bodies are integrally forged and fully welded from A182-F304/F316L forged stainless steel or LF9 low-temperature carbon steel with no split flange gaps, complying with API6D and BS6364 design codes for cryogenic valves. Nominal sizes range from DN15 to DN200 with pressure ratings of Class150 ~ Class800. The full-welded design prevents body leakage and is ideal for buried insulated piping.
Customizable Extended Valve Stem
Stem length can be customized from 50mm to 1500mm according to pipeline insulation thickness. Extra space is reserved on the extended section for thermal insulation wrapping to keep stuffing box temperature above 0℃, fundamentally blocking cold transfer to the electric actuator and avoiding motor freeze-up failure.
Electric Actuation System
Optional explosion-proof or standard electric actuators support 4-20mA analog remote signal control and local manual override. With an explosion-proof rating of Exd II BT4, the valve suits flammable and explosive working conditions such as LNG and liquid hydrogen, and can connect to DCS automatic control systems for remote on/off operation and fault signal feedback.
Cryogenic Sealing System
Seat adopts a combined sealing structure of cryogenically modified PTFE preloaded by disc springs, maintaining Class A tightness (zero leakage per ISO5208) at -196℃. Equipped with anti-static and fire-safe construction, it meets API607 fire test certification requirements.
III. Main Application Industries & Working Scenarios
LNG Energy Sector: Inlet & outlet piping of storage tanks at LNG receiving terminals, LNG tanker loading/unloading pipelines, cryogenic transfer lines for liquefaction plants (-162℃ liquefied natural gas)
Air Separation & Chemical Industry: Cryogenic storage and delivery pipelines for liquid oxygen, liquid nitrogen, liquid argon and liquid hydrogen (-196℃ cryogenic fluids)
Fine Chemicals: Process pipelines for low-temperature liquefied hydrocarbons and liquid carbon dioxide
Cold Chain Logistics: Closed conveying systems for cryogenic refrigerants
