Cryogenic Ball Valve with flanged ends: Overview, Structural Features & Technical Parameters

Cryogenic Ball Valves with flanged ends are divided into two categories: Cryogenic Floating Ball Valves and Cryogenic Trunnion Mounted Ball Valves. They are used to cut off or connect cryogenic media in pipelines, and the minimum temperature of the medium shall not be lower than -196℃. Applications of Cryogenic Valves: Chemical plants for ethylene, liquefied natural gas, etc.; natural gas LNG storage tanks, receiving terminals and satellite stations; air separation equipment, petroleum and chemical tail gas separation equipment; cryogenic storage tanks and tank trucks for liquid oxygen, liquid nitrogen, liquid argon, carbon dioxide; pressure swing adsorption oxygen production, etc.

Structural Features

• The material of the pressure-bearing components can withstand the expansion and contraction caused by the temperature change of the medium, and the structure of the sealing part will not produce permanent deformation when the temperature changes. For working conditions below -100℃, the valve parts shall undergo deep cold treatment before precision machining. That is, the parts are immersed in a liquid nitrogen tank for cooling. When the temperature of the parts reaches -196℃, heat preservation starts for 1-2 hours, then taken out of the tank for natural cooling to normal temperature, and the cycle is repeated twice.

• The valve bonnet adopts a long-neck structure, whose purpose is to protect the function of the stuffing box, keep the stuffing box away from low temperature, and ensure the sealing effect of the packing. At the same time, cold insulation materials can be wrapped to prevent cold energy loss. The neck length of the long neck can be selected according to the operating temperature and the thickness of the cold insulation material. When the sealing effect of the packing decreases, grease can be added from the middle of the stuffing box to form an oil seal layer, which reduces the pressure difference of the stuffing box and improves the sealing performance.

• When the operating temperature is lower than -100℃, the valve stem material is chrome-plated or nitrided to improve the surface hardness of the valve stem and the reliability of the packing seal.

• Cryogenic Ball Valves are equipped with an abnormal pressure rise prevention structure. Due to the drastic expansion of the volume and abnormal pressure rise of the cryogenic valve medium after gasification, when the pressure in the valve cavity rises, the valve cavity is connected with the inlet side, or a pressure relief valve is installed at the inlet end of the valve to ensure the safe use of the valve.

• The gaskets used in Cryogenic Ball Valves have reliable sealing performance and resilience at room temperature, low temperature and during temperature changes.

Technical Parameters

• Body Material: LCB, LC3, CF8, CF8M, CF3, CF3M

• Nominal Diameter: DN15-DN100

• Pressure Range: 1.6-10MPa

• Applicable Temperature: -196-80℃

• Operation Mode: Worm Gear, Pneumatic, Electric

• Applicable Media: Ethylene, Propylene, Liquid Oxygen, Liquid Nitrogen, Liquid Hydrogen, Liquefied Natural Gas, etc.