Swing Check and Wafer Check are two types of check valves used in various piping systems. While they serve the same purpose of preventing backflow, there are some key differences between them.
Design: The swing check valve has a hinged disc that swings open and closed based on the flow of fluid. It is designed with a pivot point and a hinge mechanism, allowing the disc to move freely. On the other hand, a wafer check valve consists of a disc that slides back and forth within the valve body. It is typically designed to be lightweight and compact.
Installation: Swing check valves are typically installed between flanges using bolts and gaskets. They are connected to the pipeline by welding or threadings on the flange ends. On the contrary, wafer check valves are installed between two mating flanges directly, using bolts and nuts. They require less space, making them more suitable for confined installations.
Flow characteristics: Swing check valves offer better flow characteristics due to their unobstructed flow path when the disc is fully open. This results in lower pressure drop and less turbulence. Conversely, wafer check valves may introduce slight turbulence due to the disc sliding back and forth against the valve body.
Backflow prevention: Swing check valves are highly efficient in preventing backflow as the disc closes completely under the action of reverse flow, which ensures a tight seal. Wafer check valves, on the other hand, have less effective sealing since the disc only partially covers the valve body when closed. This can lead to slight leakage during backflow if not properly installed or maintained.
Maintenance: Swing check valves are relatively easy to maintain as they can be disassembled for inspection or repair. Their design allows for easy removal and replacement of the disc and hinge mechanism if needed. Wafer check valves, however, are more difficult to access for maintenance as they are sandwiched between two flanges. In some cases, the entire valve may need to be removed for repair or replacement.
Applications: Swing check valves are commonly used in applications where high flow rates and minimal pressure drop are required. They are suitable for liquid, gas, and steam services in industries such as water treatment, oil and gas, and power generation. Wafer check valves are typically used in applications with limited space and lower flow rates, such as HVAC systems, irrigation, and fire protection systems.
While both swing check and wafer check valves serve the essential function of preventing backflow in piping systems, their design, installation, flow characteristics, backflow prevention, maintenance requirements, and applications differ. It is important to select the appropriate type of check valve based on the specific requirements of the system to ensure efficient and reliable operation.
Post time: Nov-13-2023