The Differences Between Swing Check Valves, Lift Check Valves, and Butterfly Check Valves

The disc of swing check valves rotates around the hinge pin inside the seat. It opens and closes automatically relying on the disc weight and fluid pressure, so as to prevent the medium backflow. Due to the linear shape of the channel inside the valve, the flow resistance is smaller than lift check valves, making it suitable for large diameter applications with low flow rates and infrequent flow changes. However, the sealing performance cannot surpass that of lift check valves. It is applied to various media such as water, steam, oil, nitric acid, acetic acid, strong oxidizing media, and urea.

The disc of lift check valves moves up and down along the centerline of the valve body. Lift check valves can only be installed on the horizontal pipelines. The disc opens and closes automatically depending on the flow of the medium itself to prevent medium backflow. The body shape is similar to globe valves, thus the fluid resistance is relatively high.

Butterfly check valves can be installed both on the horizontal and vertical pipelines. It is usually wafer connected. Under the action of fluid pressure, the two discs overcome spring force and rotate around the hinge pin. The structure is similar to butterfly valves. But as the cut-off valves, butterfly valves must be operated by external force, while butterfly check valves are not, that is they work automatically.