一、进口低温液氮止回阀概述

进口低温液氮止回阀，Cryogenic liquid nitrogen check valve，又称低温逆止阀、低温单向阀、低温逆流阀、和低温背压阀，是指采用经过低温深冷的不锈钢材质，在低温贮槽上或者低温管道系统，依靠介质本身流动而自动开、闭阀瓣，防止低温介质液氧，液氮，液氩，液化天然气，LO2、LN2、LAR、LNG等倒流的阀门，

美国威盾VTON低温液氮止回阀结构紧凑、体积小、重量轻，防止倒流零泄露，稳定性好。

液氮（常写为LN2），是氮气在低温下形成的液体形态。氮的沸点为-196°C，在正常大气压下温度如果在这以下就会形成液氮；在工业中，液态氮是由空气分馏而得。先将空气净化后，在加压、冷却的环境下液化，借由空气中各组分之沸点不同加以分离。氦气最先泄出(且未被液化)，接着就是占空气中78.09%的氮气，再来是占20.95%的氧气，最后是占空气中0.93%的氩气。

Low temperature liquid nitrogen check valve, Cryogenic liquid nitrogen check valve， Also known as low-temperature check valve, low-temperature one-way valve, low-temperature backflow valve, and low-temperature backpressure valve, it refers to a valve made of stainless steel material that has undergone low-temperature deep cooling, which automatically opens and closes the valve disc on a low-temperature storage tank or low-temperature pipeline system, relying on the flow of the medium itself to prevent the backflow of low-temperature medium such as liquid oxygen, liquid nitrogen, liquid argon, liquefied natural gas, LO2, LN2, LAR, LNG, etc,

The American Weidun VTON low-temperature liquid nitrogen check valve has a compact structure, small volume, light weight, and prevents backflow and zero leakage, with good stability.

Liquid nitrogen (often written as LN2) is a liquid form of nitrogen formed at low temperatures. The boiling point of nitrogen is -196 ° C, and under normal atmospheric pressure, if the temperature is below this, liquid nitrogen will form; In industry, liquid nitrogen is obtained by air distillation. After purifying the air, it liquefies under pressure and cooling, and is separated by the different boiling points of each component in the air. Helium gas is first released (and not liquefied), followed by nitrogen gas accounting for 78.09% of the air, followed by oxygen gas accounting for 20.95%, and finally argon gas accounting for 0.93% of the air.

二、进口低温液氮止回阀参数