Spring check valve is an automatic valve that uses spring force to assist the valve disc to close quickly. It is a special design type of check valve. Its core function is to block the backflow of the medium and enhance the sealing performance through the spring. It is suitable for scenes with high requirements for sealing efficiency and closing speed.
1. Structure and working principle
Core component design
Valve disc: a circular or disc-shaped structure, usually made of stainless steel or composite materials; Spring: installed between the valve disc and the valve body, providing preload to accelerate the closing action; Sealing surface: the valve seat is covered with elastic materials (such as rubber or polytetrafluoroethylene) to enhance low-pressure sealing performance.
Action principle
Opening process: when the medium flows forward, the spring preload force is overcome to push the valve disc open; Closing process: when the medium flow rate decreases or reverses, the spring force quickly resets the valve disc to block the backflow.
2. Performance Advantages and Limitations
| Terms | illustrate |
|---|---|
| Sealing | Spring preload makes up for insufficient sealing in low-pressure conditions, reducing leakage rate by 80% compared to traditional swing-type |
| Response speed | Closing time ≤ 0.2 seconds (compared to 0.8-1.5 seconds for spring-free swing type) |
| Applicable media | Clean liquid or gas (such as clean water, compressed air), suspended matter needs to be pre-filtered (content ≤ 0.1%) |
Limitations:
The spring may fail due to long-term corrosion by the medium and needs to be replaced regularly (recommended maintenance cycle ≤ 500 hours);
High viscosity or particle-containing media can easily cause spring jamming.
3. Typical application scenarios
Low-pressure closed circulation system
Such as laboratory pure water circulation pipelines and HVAC systems, which rely on springs to close quickly to prevent backflow pollution;
Frequently started and stopped pump group protection
Springs assist in shortening the closing time to avoid the medium backflow impacting the impeller when the pump is stopped;
Vertically installed pipelines
The spring force overcomes the influence of gravity to ensure that the valve disc is reliably closed in the vertical flow direction
4. Comparison with other check valves
| Terms |
Speing Loading Check Valve |
Swing Check Valve |
|---|---|---|
| Shut down power | Spring force + medium pressure | Medium pressure + gravity |
| Applicable pipe diameter | Mainly small diameter (DN≤50mm) | Mainly large diameter (DN ≥ 50mm) |
| Noise Level | ≤50dB (spring buffer impact) | 70-85dB (direct collision with metal parts) |
