Check Valve vs Relief Valve – What’s the Difference

Check Valve vs Relief Valve

When it comes to pipeline systems, valves play a vital role in ensuring the safe and efficient flow of fluid or gas. Among the many types of valves, the check valve and the relief valve are commonly used, yet they differ in their function and use. This blog post will explore the differences between these two valve types and help you understand which is most suitable for your pipeline system.

Difference Between Check Valve and Relief Valve


The primary function of a check valve is to prevent backflow of fluid in a pipeline. It operates automatically and allows fluid to flow in one direction only. On the other hand, a relief valve is designed to relieve pressure in a pipeline system if the pressure exceeds a predetermined level. It operates manually or automatically and helps prevent pipeline failure due to overpressure.


A check valve typically consists of a movable disc or ball, allowing fluid flow in only one direction. When the fluid tries to flow back, the disc or ball moves to block the flow, thereby preventing backflow. A relief valve, on the other hand, has a spring-loaded mechanism to ensure that the valve remains closed until the pressure in the pipeline exceeds a pre-set level. Once this level is reached, the valve opens to release the excess pressure.


Check valves are commonly used in pipeline systems like wastewater treatment facilities, oil and gas pipelines, and water supply systems, where backflow prevention is critical. They are used when the system must maintain a specific pressure and flow rate. Relief valves, on the other hand, are used in pipeline systems where pressure build-up can cause damage or failure. They are commonly found in steam, hydraulic and pneumatic systems.


Check valves come in various types, such as Swing Check, Tilting Disc Check, and Ball Check Valves, among others. Each check valve type has a unique design and offers different features and benefits. Relief valves also come in different types, including Safety Relief Valves, Pressure Relief Valves, and Thermal Relief Valves. Each type of relief valve serves a specific purpose and is designed to address the specific needs of a pipeline system.


Both check valves and relief valves require regular maintenance to ensure they function correctly. Check valves may need cleaning to remove debris that can prevent them from sealing properly. Relief valves, on the other hand, need periodic testing and adjustment to ensure the pressure setting is still correct. Failure to maintain these valves can lead to the system’s catastrophic failure, resulting in costly repairs and downtime.


In summary, check and relief valves are essential components of pipeline systems. While they have some similarities, they differ significantly in function, design, application, and maintenance. Choose the right valve type for your pipeline system, depending on the fluid or gas, pressure, and flow rate requirements. Remember to maintain them regularly to ensure peak performance and avoid costly downtime.



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