Circular symbol with an arrow

Circular symbol with an arrow The symbol of a check valve on a drawing is usually represented as a circular symbol with an arrow, the arrow points in the direction of the medium’s flow. This symbol is used to intuitively represent the one-way flow characteristic of the check valve, ensuring that the can only flow in one direction, thus preventing backflow. 1 2 Basic information of check valve A check valve is an automatic valve that opens and closes relying on the pressure of the medium, mainly used to prevent the backflow of the medium. Its structural characteristics include: Short structural length: Its structural length is only1/4 to 1/8 of that of traditional flanged check valves. Small volume and light weight: The weight is only 1/4 to /20 of that of traditional flanged check valves. Quick valve disc closing: Low water hammer pressure. Diverse materials: It can use a variety of metal such as carbon steel, low-temperature steel, and duplex steel. Classification and function of check valves Check valves can be divided into lift type and swing type according the movement mode of the valve disc. The lift type check valve is similar in structure to a gate valve, while the valve disc of the swing type check valve can around the shaft. Check valves are often used as bottom valves in water lifting devices, which can prevent the backflow of water and are used in combination with gate valves play a safe isolation role.