Time：2025-03-26Views：2
Slow closing check valve is a valve that combines a slow closing mechanism with a check function, mainly used to prevent medium backflow and eliminate water hammer phenomenon. The following is an analysis of the structural characteristics, operating principles, and advantages of the valve.
1、 Structural characteristics
1. Compact design
The structural length is only 1/4~1/8 of traditional flange check valves, with a small volume, light weight, and easy installation and maintenance.
Smooth flow channel, low fluid resistance, suitable for horizontal or vertical pipelines.
2. Slow closing mechanism
Built in slow closing devices (such as hydraulic buffers, damping cylinders, etc.) control the closing speed of the valve disc by adjusting the opening of the needle valve or ball valve.
The stroke of valve disc is short, the impact force is small when closing, and the Pressure of water hammer is significantly reduced.
3. Sealing performance
Using rubber soft seal or metal hard seal to ensure zero leakage between the valve disc and seat.
Sealing materials are wear-resistant and corrosion-resistant, suitable for various media such as water, steam, oil, chemical media, etc.
4. Various Material
The valve body Material can be carbon steel, stainless steel, acid and alkali resistant alloy, etc., to meet the needs of different working conditions.
Some designs adopt double or triple eccentric structures to reduce the friction of the sealing surface and extend its service life.
2、 Working principle
1. Opening process
When the medium flows in the positive direction, the valve disc opens rapidly under the action of Pressure, and the medium flows downstream through the valve.
The slow closing mechanism does not participate in the opening process to ensure rapid response of the valve.
2. Closing process
When the medium flows back or the pump stops suddenly, the valve disc starts to close under the action of Pressure at the outlet end.
Slow closing mechanisms (such as damping cylinders) slow down the closing speed of the valve disc through throttling, causing the valve to close in stages (quickly closing 80% first, then slowly closing the remaining 20%).
This process effectively eliminates the phenomenon of water hammer and protects the safety of pipelines and equipment.
3、 Core advantages
1. Eliminate water hammer
The slow closing function can significantly reduce the water hammer Pressure when the valve is closed to avoid damage to pipes and equipment.
2. High sealing performance
Advanced sealing technology and materials ensure zero leakage when the valve is closed, preventing medium backflow.
3. Corrosion resistance and long lifespan
Choose corrosion-resistant materials to adapt to complex working conditions; Precision manufacturing processes and slow closing mechanisms extend the service life of valves.
4. Low noise and energy efficiency
Slow closing process reduces noise pollution; Low flow resistance and significant energy-saving effect.
5. Widely used
Suitable for pump outlets in industries such as water supply systems, HVAC, petrochemicals, and power to protect the safe operation of equipment.
4、 Typical application scenarios
1. High rise building water supply: prevent water hammer damage to pipelines and equipment during pump shutdown.
2. Petrochemical industry: transporting corrosive media to prevent backflow and ensure safe production.
3. Power system: used for cooling water systems to protect equipment from water hammer impact.
Slow closing check valves play an important role in the field of fluid control due to their intelligent slow closing mechanism, compact structure, and excellent sealing performance, providing strong guarantees for the safe and stable operation of industrial pipelines.