Difference Between Check Valve And Backflow Preventer
Check valves and backflow preventers are two essential components in plumbing systems that are responsible for preventing the backward flow of liquids. These highly important devices play an important role in preventing cross-connections and backflows that can lead to contamination in your water supply.
Let’s take a closer look at the differences between a check valve and backflow preventer.
Check Valve
A check valve, also referred to as a non-return valve, is a simple mechanism used to allow water to flow in only one direction and prevent backflow. It consists of a moving element that opens the valve in the forward direction and closes it tightly in the reverse direction.
Check valves are commonly used in applications such as water and sewage pumping systems, irrigation, and steam condensate systems. They are also used in the oil and gas industry, in pharmaceuticals, and in many other industrial applications.
When the water flows through a check valve in the right direction, the valve disk is lifted in response to the pressure exerted by the fluid flow. Once the flow stops, the valve disk falls back and seals the valve tight, preventing any backward flow.
Check valves are typically installed in a horizontal or vertical position, depending on the application. They are available in a wide range of sizes, shapes, and materials, including stainless steel, brass, plastic, and PVC.
Backflow Preventer
A backflow preventer is a more sophisticated device that is commonly used in water supply systems to ensure water quality and safety. A backflow preventer works by allowing water to flow in one direction while preventing backflow in the other direction.
Backflow preventers are installed in your home’s water supply lines where the lines connect to city water mains, in irrigation systems, or in other water systems where there is a potential for backflow.
In contrast to check valves, backflow preventers have a series of diaphragms and springs that respond to changes in water pressure. If there is a sudden drop in water pressure or a vacuum is created in the water supply line, a backflow preventer valve will close to protect against backflow.
Backflow preventers come in many different types, including air gap, reduced pressure zone, and double-check valve assemblies. Each of these has its own function and is designed for use in specific applications.
Key Differences between Check Valves and Backflow Preventers
The most significant differences between check valves and backflow preventers are typically summarised as follows:
1. Functionality: Check valves only allow the flow of water in one direction, while backflow preventers allow the flow of water in one direction and prevent backflow in the opposite direction.
2. Design: While both devices have moving elements, check valves have a simple design consisting of a movable disc that seals the chamber, whereas backflow preventers have a more complex design consisting of multiple diaphragms and springs that respond to changes in pressure.
3. Application: Check valves are used in a wide range of applications, including pumping systems, irrigation, and steam condensate systems. On the other hand, backflow preventers are primarily designed to prevent backflow in water supply lines, irrigation systems, and other applications where a cross-connection is possible.
4. Types: Both devices come in various forms, including swing, lift, ball, and piston-type check valves and air gap, double-check valve assembly, and reduced pressure zone backflow preventers.
Conclusion
In summary, check valves and backflow preventers are two vital components of plumbing systems that play a significant role in protecting water quality and safety. Knowing the difference between the two devices is essential to selecting the right one for the right application.
Whether you’re looking to install a check valve or a backflow preventer, always ensure the device you choose meets your specific needs and complies with all relevant regulations and standards for your area.
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Difference Between Check Valve And Backflow Preventer
