I. Comparison of core features and performance
Differences in working principles
Swing type: The valve disc is opened and closed by rotating around the axis, mainly relying on the medium pressure to push the valve disc open, and closing by self-weight or medium back pressure in the reverse direction.
Spring type: The valve disc is closed with the assistance of spring preload. The forward flow needs to overcome the spring resistance to open, and the reverse pressure can quickly trigger the spring rebound to achieve sealing.
Applicable media and scenarios
Advantages of swing type:
The flow channel is approximately straight, with low resistance, suitable for large-diameter pipes with DN≥200 (such as municipal water supply and industrial sewage);
It can withstand particles and high-viscosity media (mud, sewage), and can extend its life through wear-resistant valve discs;
No auxiliary spring is required when installed vertically, and it can be closed by self-weight.
Advantages of spring type:
Spring preload enhances sealing, suitable for high-pressure (≥1.6MPa) small-caliber systems (such as home heating, precision instrument protection);
Fast response speed, closing time ≤0.5 seconds, effectively reducing water hammer impact force by more than 60%;
Suitable for clean liquid environment (pharmaceutical, pure water system), to avoid particles blocking the spring.
Maintenance and lifespan
Swing type: No spring assembly, check valve disc wear and pin lubrication every 2 years, lifespan up to 8-10 years;
Spring type: Springs need to be replaced regularly (every 1-2 years), and springs are prone to fatigue failure under long-term high-pressure conditions.
II. Selection decision points
Conditions for giving priority to swing check valves
Large flow and low-pressure systems: such as municipal drainage, petrochemical pipelines (DN≥200);
Medium containing solid particles: Wear-resistant discs (hard alloy overlay) and soft seal design are required;
Vertical installation requirements: No additional spring assistance is required, closed by gravity.
Conditions for giving priority to spring check valves
High-pressure small-diameter scenarios: such as air-conditioning pipes (DN≤40), independent home heating systems;
Quick response to needs: prevent water pump reversal, protect precision instruments;
Clean liquid environment: high-purity liquid transportation, avoid particle obstruction.
III. Typical case references Municipal drainage system: swing check valve (double-flap design), resistant to sediment erosion, low maintenance cost; Home wall-mounted boiler heating: spring check valve, quickly block hot water backflow, reduce water hammer noise; Chemical high-pressure pipeline: swing check valve (soft seal improved type), corrosion-resistant and adaptable to pressure fluctuations.
IV. Summary
There is no absolute superiority or inferiority between the two check valves. The core selection logic is:
Containing particles/large flow → choose swing type (improved soft seal);
High pressure/fast response → choose spring type (suitable for clean media);
Vertical installation/maintenance-free → give priority to swing type;
Horizontal pipeline/precision protection → give priority to spring type