The structural design features and installation requirements of the ultra-low temperature pneumatic ball valve are applicable to the valve working in the cryogenic cryogenic working condition, which is called the cryogenic valve. In the valve industry, all valves below - 40 ℃ are called cryogenic valves. Ultra cryogenic valves below - 101 ℃ are generally used in cryogenic systems such as liquid helium, liquid hydrogen, liquefied natural gas and air separation. The medium used is liquid helium, liquid hydrogen, liquefied natural gas, liquid nitrogen, liquid oxygen and other cryogenic fluids. Low temperature stop valves are commonly used in low temperature environments. In some special environments, cryogenic pneumatic ball valves, cryogenic gate valves and cryogenic butterfly valves are also used. Under low temperature conditions, the conventional metal hard seal and non-metallic soft seal cannot meet the sealing requirements. In order to ensure the safe and reliable operation of cryogenic valves at low temperature, the structural design features and installation requirements of ultra-low temperature pneumatic ball valves.

(4) The electromagnetic flowmeter has no mechanical inertia and flexible response. It can measure the instantaneous pulsating flow, as well as the flow in both positive and negative directions.