Where should a check valve be placed?

When considering the installation location of check valves, it's vital to determine the right placement to ensure optimal function and system efficiency. Understanding the implications of where to place a check valve can significantly affect the operation of your hydraulic systems.

Check valves, also known as non-return valves, serve the critical purpose of allowing fluid to flow in one direction while preventing backflow. This automatic feature is essential for maintaining system pressure and ensuring that pumps operate efficiently.

Key Installation Considerations for Check Valves

The installation position of a check valve can broadly be classified into two primary options: before or after the pump. Each position has its own set of advantages and is suited for specific applications.

Check Valve Positioned Before the Pump

When a check valve is installed at the end of the vertical suction pipe in front of the pump, it is commonly referred to as a "bottom valve." This setup is designed to enable the pump to be self-priming. When there is no liquid in the suction line, the check valve prevents air from entering the pump, effectively allowing it to maintain its prime.

This installation approach ensures that the pump is filled with liquid before it starts operating, provided that the fluid's source is below the pump's liquid level. It is crucial in applications where a steady supply of fluid is required without interruption.

Check Valve Positioned After the Pump

In scenarios where the liquid level is higher than the pump, placing the check valve after the pump allows for more straightforward operation during start and shutdown sequences. This configuration eliminates the need to close the water outlet valve of the pump, which is particularly advantageous in systems where backflow needs to be prevented effectively.

An important note from industry experts, including manufacturers like Huade Hydraulic, is that check valves should be placed at the pump's outlet and in front of the outlet control valve for easier maintenance. Typically, the first outlet of the pump is a soft connection, followed by the check valve, and then the block valve.

Guidelines for Check Valve Installation

When deciding on the positioning of the check valve, consider the following guidelines:

• 1. Install the check valve first, followed by a gate valve or butterfly valve. This method protects the check valve and ensures that any pressure from pump startups does not damage it.
• 2. Alternatively, install the gate or butterfly valve before the check valve. This approach protects the gate or butterfly valve, making them easier to maintain.

Given that check valves experience frequent opening and closing events, the potential for wear and tear is higher. Therefore, positioning them before the outlet gate valve or butterfly valve is often recommended as it facilitates easier repairs without shutting down the entire system.

Considerations for Specific Applications

In systems with multiple pumps running in parallel, the proper placement becomes even more critical. If one pump needs to be taken offline for maintenance, the isolation of the entire system can be achieved by carefully considering the placement of these valves. Overall, effective check valve installation dramatically influences the system's safety, reliability, and operational efficiency.

For more information about the application of different types of check valves, such as the Right Angle Check Valve, and their specific use-cases, visit our resource pages.

Learn more about the function and benefits of the 2-Way Hydraulic Solenoid Valve to see how these systems can be optimized in your applications.