一、进口升降式止回阀概述

进口升降式止回阀，Lift check valve，是指阀瓣利用流体压差和自身的重量实现升降，来防止介质倒流的止回阀，适用于大部分的罐内水平管路上，自动阻止介质逆流，保护上游设备。具有结构简单，动作可靠，维修方便等优点，广泛应用于净化设备、石油、化工、冶金、电力、轻纺等生产过程中。

美国威盾VTON升降式止回阀原理是当介质由阀体箭头所示流向进入阀体，介质的压力作用在阀瓣上产生向上的推力，当介质推力大于阀瓣重力时，阀门打开。当阀后介质压力作用在阀瓣上的力加上阀瓣自身重力大于阀前压力作用在阀瓣上的力时，阀门关闭，阻止介质倒流。主要产品有：升降式法兰止回阀，铸钢升降式止回阀，不锈钢升降式止回阀，水用升降式止回阀，蒸汽用升降式止回阀，气体用升降式止回阀。

Lift check valve, Lift check valve， It refers to a check valve that uses the fluid pressure difference and its own weight to lift and lower the valve disc to prevent medium backflow. It is suitable for most horizontal pipelines in tanks, automatically preventing medium backflow and protecting upstream equipment. It has the advantages of simple structure, reliable operation, and convenient maintenance, and is widely used in production processes such as purification equipment, petroleum, chemical industry, metallurgy, power, and light textile.

The principle of the American Weidun VTON lift check valve is that when the medium flows into the valve body as indicated by the arrow on the valve body, the pressure of the medium acts on the valve disc to generate an upward thrust. When the medium thrust is greater than the gravity of the valve disc, the valve opens. When the force exerted by the pressure of the medium behind the valve on the valve disc plus the gravity of the valve disc itself is greater than the force exerted by the pressure before the valve on the valve disc, the valve closes to prevent the medium from flowing back. The main products include: lifting flange check valves, cast steel lifting check valves, stainless steel lifting check valves, water lifting check valves, steam lifting check valves, and gas lifting check valves.

二、进口升降式止回阀产品参数

1、口径：DN15-3000，1/4-100寸

2、压力：PN0.6-PN320；Class150LB-2500LB；JIS10K-20K

3、温度：-196℃-550℃

4、阀体材质：铸铁，球铁，铸钢，不锈钢，铬钼钢

5、密封面：堆焊铬不锈钢、堆焊硬质合金、铬镍钛不锈钢

6、垫片：钢带石墨参缠绕、聚四氟乙烯

7、连接方式：法兰，螺纹、焊接

8、使用介质：水、蒸汽、油品等

三、进口升降式止回阀主要外形图