What is a swing check valve?
A swing check valve, also known as a micro-stop check valve or non-return valve, is a valve that automatically prevents backflow of fluid. Its primary function is to prevent backflow of media in pipelines, ensuring that media flow is restricted to one direction, thereby avoiding accidents.
How does a swing check valve work?
The opening and closing member (disc) of a swing check valve rotates around a rocker shaft within the valve body. When fluid flows in the forward direction, the disc opens under the action of fluid pressure, allowing the media to pass through. When fluid pressure decreases or reverse flow occurs, the disc closes under the action of its own weight and the pressure of the counterflowing fluid, preventing backflow.
What is the structure and components of a swing check valve?
A swing check valve primarily consists of a valve body, bonnet, disc, and rocker. The disc is disc-shaped and rotates around a pin outside the valve seat passage. The valve's internal passage is streamlined, resulting in relatively low flow resistance, making it suitable for large-diameter pipes.
Swing Check Valves Classification and Applications
Depending on the number of discs, swing check valves can be categorized as single-disc swing, double-disc swing, and multi-disc swing. Different types of swing check valves are suitable for different applications:
- Single-disc swing check valves are generally suitable for medium-diameter applications. When using single-disc swing check valves for large-diameter pipelines, slow-closing check valves are recommended to reduce water hammer pressure.
- Double-disc swing check valves are suitable for medium- and large-diameter pipelines.
- Swing check valves are also widely used in automatic sprinkler systems, water supply and drainage pipelines, and fire hydrant water supply systems to improve efficiency and ensure the normal flow of people's lives.
Features and Advantages of Swing Check Valves
Swing check valves have the following features and advantages:
- Low flow resistance: The streamlined design of the valve passageway reduces resistance to fluid flow.
- Effortless Opening and Closing: The disc opens and closes via a rotational motion, requiring less effort than lift check valves.
- Corrosion-Resistant: The valve body, disc, and other components are constructed of corrosion-resistant materials, making them suitable for use with corrosive media.
- Versatile: They can be installed in horizontal, vertical, or inclined pipelines, adapting to a variety of installation locations and media types.
