How does a check valve achieve the opening and closing of the valve? Opening and closing of check valve: The opening and closing parts are circular discs and act on their own weight and medium pressure to block medium backflow. The medium flows in from the inlet end (lower side) and out from the outlet end (upper side). How does the inlet pressure check valve achieve the opening and closing of the valve?

止回閥閥門的打開和關閉：啟閉件為圓形閥瓣并靠自身重量及介質壓力產生動作來阻斷介質倒流。

Opening and closing of check valve: The opening and closing parts are circular discs and act on their own weight and medium pressure to block medium backflow.

介質從進口端(下側)流入，從出口端(上側)流出。當進口壓力大于閥瓣重量及其流動阻力之和時，閥門被開啟。反之，介質倒流時閥門則關閉。旋啟式止回閥有一個斜置并能繞軸旋轉的閥瓣，工作原理與升降式止回閥相似。

The medium flows in from the inlet end (lower side) and out from the outlet end (upper side). When the inlet pressure is greater than the sum of the weight of the valve disc and its flow resistance, the valve is opened. On the contrary, when the medium flows back, the valve closes. The swing check valve has a valve disc that is tilted and can rotate around the axis, and its working principle is similar to that of a lift check valve.

止回閥常用作抽水裝置的底閥，可以阻止水的回流。止固閥與截止閥組合使用，可起到隔離的作用。缺點是阻力大，關閉時密封性差。

A check valve is commonly used as the bottom valve of a pumping device to prevent water from flowing back. The combination of a check valve and a shut-off valve can provide safe isolation. The disadvantage is high resistance and poor sealing when closing.

擴展資料：

Extended Information:

止回閥按結構劃分，可分為升降式止回閥、旋啟式止回閥和蝶式止回閥三種：

Check valves can be divided into three types according to their structure: lift check valves, swing check valves, and butterfly check valves:

1、升降式止回閥分為立式和臥式兩種。

1. Lift check valves are divided into two types: vertical and horizontal.

2、旋啟式止回閥分為單瓣式、雙瓣式和多瓣式三種。

2. Swing check valves are divided into three types: single disc, double disc, and multi disc.

3、蝶式止回閥為直通式。

3. The butterfly check valve is a straight through type.