Full analysis of check valve types for Roots blower**
**From structural principles to selection decision trees**
**1. Mainstream technical characteristics**
-* * Swing check valve**
-Structure: Single or multiple hinged design
-Advantage: Large circulation capacity (Cv value ≥ 450)
-Limitations: prone to water hammer when closed, not suitable for pulsating flow fields
-Lift check valve**
-Structure: Vertical moving valve disc+guide sleeve
-Advantage: The sealing level can reach VI level (zero leakage)
-Limitations: High pressure loss (Δ P ≥ 0.15MPa)
-* * Clamp type check valve**
-Structure: Butterfly valve disc+spring assisted closure
-Advantages: Small size, light weight (reduced by 40% compared to traditional models)
-Limitations: Only applicable to pipelines ≤ DN300
**2. Selection Decision Model**
Establish a four-dimensional evaluation system:
1. Flow requirements: When Q>100m3/min, double flap swing type is preferred;
2. Pressure fluctuations: Spring assisted type is required for pulsation frequencies greater than 10Hz;
3. Space limitation: When the installation length is less than 3D, choose the clamp type;
4. Maintenance cycle: It is recommended to use fully lined fluorine valves for chemical environments.
