How to Correctly Install Check Valve in Pipeline Systems

 
In the design and maintenance of pipeline systems, the proper installation position of check valves and their effective coordination with other valves are critical factors in ensuring system safety and reliability. Below, we will delve into a more detailed discussion of the selection of check valve installation positions, classification, and their coordination with other valves.
 

1. Function and Classification of Check Valves

 
Check valves, as automatic valves, serve the primary function of preventing the backflow of fluids within pipeline systems, thereby ensuring the safe operation of the pipelines. Depending on their structure and connection methods, check valves can be classified into various types such as lift-type, swing-type, and butterfly-type. Different types of check valves exhibit different applicability and characteristics in various scenarios.
 

2. Selection of Installation Positions

 
Installation Before the Pump: This method is suitable when the fluid level is lower than the pump. By installing the check valve before the pump, it ensures that the pump is fully primed with fluid upon startup, avoiding the risk of dry running and failure.
 
Installation After the Pump: This approach is preferable when the fluid level is higher than the pump. Installing the check valve after the pump facilitates the startup and shutdown of the pump without the need to close the discharge valve, effectively preventing backflow.
 

3. Coordination with Other Valves

 
Check valves often need to collaborate with other valves such as gate valves, butterfly valves, etc., to achieve precise control and maintenance of the pipeline system. When determining the sequence of coordination with other valves, various factors need to be considered, including valve protection, equipment lifespan, and ease of maintenance.
 
Check Valve Installation Before Gate or Butterfly Valves: This approach effectively protects the check valve, especially in parallel pump systems. When one pump stops running and its discharge valve closes, the other pump's startup is supported by the gate or butterfly valve, thereby safeguarding the check valve.
 
Check Valve Installation After Gate or Butterfly Valves: While this method protects the gate or butterfly valve, it requires attention to the check valve's lifespan and stability. Significant pressure fluctuations within the pipeline system may cause the check valve to frequently open and close, potentially affecting its lifespan and stability.
 
The prudent selection of check valve installation positions, combined with the coordination with other valves, is a crucial measure in ensuring the safe and reliable operation of pipeline systems. Through a comprehensive understanding of the characteristics and functions of various valves, pipeline systems' stability and reliability can be effectively safeguarded, providing robust support for the smooth progress of engineering projects.