As we get deeper into the plumbing and fluid management world, we come across different terms that must be clarified. Today, we’ll discuss two essential valves in this sector – Check Valves and Double Check Valves. Both these valves work differently and serve different purposes, but users can easily misunderstand their purpose and application. In this article, we’ll break down the differences between these valves and help you choose the best valve for your needs.
Difference Between Check Valve and Double Check Valve
Purpose and Function –
Check valves allow fluid to flow in only one direction and prevent backflow. When fluid pressure is applied in one direction, the check valve opens the gate, allowing the fluid to pass through. The valve gate closes in the reverse flow direction, preventing fluid from flowing backwards.
Double check valves, on the other hand, are designed to prevent backflow. They are used to safeguard against contamination of drinking water and are installed at residential and commercial water supply systems. Double check valves use two independently acting check valves to prevent backflow, which makes it the ideal choice for solutions that require maximum backflow protection.
Physical Structure –
A check valve usually has a simple design, with only one moving part to control fluid flow. It commonly comprises a valve body, bonnet, and clapper assembly. The clapper moves along with the shaft in the same direction as the fluid flow to open the valve. A check valve is typically smaller and more compact than a double check valve.
Double check valves are larger than check valves, have a more complex structure, and involve a series of two check valves with an intermediate chamber. Although these valves are larger, they still offer significant backflow protection because of the double layer of backflow prevention.
Check valves can be mounted in any position, horizontal or vertical, while double check valve devices must be in a horizontal position for proper operation. Check valves require minimal installation space, a key benefit for compact applications. Double check valves, however, require ample space due to their larger size.
Check valves are relatively low maintenance, as they have a simple design with few moving parts that need little attention. They need to be inspected regularly to ensure that they are functioning correctly.
Double check valves are more complex and often used for critical applications than check valves. They require more regular maintenance and testing to verify their proper functioning.
Check valves have a price advantage, as they are relatively cheaper due to their simple construction. They are ideal for low-budget applications as they are cost-efficient and provide efficient operation. On the other hand, double check valves are often more expensive due to their complex design, but the added level of protection they provide is worth the extra cost in applications where backflow contamination is a hazard.
In summary, choosing the right valve for your specific application is essential. Check valves are perfect for simple systems that require one-way fluid flow, while double check valves are more suitable for applications that require backflow prevention. Double check valves offer added protection since they have two independently working check valves. Though check valves are more cost-effective, double check valves are ideal for higher-risk systems. By understanding the differences between these valves, you can make an informed choice and select the ideal valve that meets your system’s specific demands.