A slow-closing check valve is a type of valve that prevents backflow of media in a pipeline and effectively buffers water hammer impact generated when the valve closes.
Structural Features
Compact and Lightweight: Short in length, typically only 1/4 to 1/8 the size of a traditional flanged check valve; small in size and light in weight, only 1/4 to 1/20 the weight of a traditional flanged check valve.
Diverse Valve Disc Designs: Common designs include swing-type single-disc and lift-type structures. Some slow-closing check valves use a double-eccentric or triple-eccentric butterfly disc as the valve disc, such as the butterfly slow-closing check valve, which allows for better contact with the valve seat when closed, improving sealing performance.
Buffering Components: Built-in buffering components such as hydraulic cylinders, springs, and damping devices are used to control the closing speed of the valve disc.
Working Principle
Forward Flow: When the media flows in the specified direction, the pressure of the media pushes the valve disc open, allowing the media to pass smoothly through the valve.
Reverse Flow and Buffering: When the medium flows backward, the valve disc, under the combined action of its own weight, the reverse pressure of the medium, and the buffer components, first quickly closes most of the passage, then slowly closes the remaining portion, effectively eliminating destructive water hammer peaks.
Performance Advantages
Reliable Check Fluidity: Effectively prevents backflow of the medium, ensuring unidirectional flow of the medium in the pipeline system and protecting the safe operation of equipment and pipelines.
Good Water Hammer Suppression: Through the buffer device, the water hammer pressure generated when the valve is closed can be significantly reduced, avoiding damage to the pipeline system, pumps, and other related equipment caused by water hammer.
Low Fluid Resistance: The valve's internal flow channel design is reasonable, minimizing obstruction to medium flow when the valve disc is open, reducing energy consumption.
Excellent Sealing Performance: Utilizing high-quality sealing materials and advanced sealing structures, it ensures good sealing performance of the valve in the closed state, preventing medium leakage.
Application Areas
Water Supply and Drainage Systems: Widely used in municipal, building, and other fields of water supply network systems and sewage treatment systems, installed at the pump outlet to prevent water backflow and water hammer phenomena.
Industrial Piping: Used in piping systems of chemical, power, and metallurgical industries to prevent backflow of various fluid media and protect the normal operation of production equipment and processes.
Common Types
300X Slow-Closing Check Valve: Composed of a main valve, check valve, needle valve, ball valve, miniature filter, and pressure gauge, this hydraulically controlled piping system automatically controls the opening and closing speed of the main valve to prevent water hammer.
HH44X Low-Resistance Slow-Closing Check Valve: Offers low resistance to water flow when the valve disc opens, requiring only one-fifth the opening force of a traditional swing valve, resulting in energy savings. The latter part of the valve disc's closing stroke is equipped with a damping device with adjustable damping time to prevent destructive water hammer.
Slow-closure Check Valve factory
