Water check valves are one of many manifestations of the popular and highly useful check valve, a valve that oversees and ensures unidirectional fluid flow. Water check valves are much like their cousins, but instead of controlling the flow of any liquid or gas, water check valves work only with water. Water check valves are essentially backflow prevention devices, meaning that they prevent water from flowing in the wrong direction and causing malfunction. In the case of potable water, backflow is especially dangerous because it could cause pollution or contamination. Water check valves are used in a variety of systems, such as fire hydrants, dishwashers, irrigation systems, water mains, domestic and commercial washing machines, plumbing systems and rainwater harvesting systems.
Generally speaking, most water check valves are composed simply of an inlet port, an outlet port and a stopper mechanism. To work, water flows in through the inlet port, where it puts forward-direction pressure on the valve. A properly functioning valve will respond by allowing the stopper mechanism to displace slightly. It will only open in one direction; the pressure from a flow from the other side, rather than opening it, will create an airtight seal by pushing the stopper back into its hole, and the valve will only open again when the forward pressure is greater than the back pressure.
To accommodate the diverse applications that they serve, water check valves come in a variety of sizes and styles. The diameter of the stopping device, which may be a ball, a piston or a disc, is very important in terms of to what it is mounted; if the passageway to which the valve is mounted is smaller than the valve, it cannot be used. Thus, customers must take special care to note diameter sizes when they are shopping for valves for their applications. Common styles incorporated into the water check valve world include ball valves, diaphragm check valves, tilting disc check valves, stop-check valves, lift-check valves, inline check valves, duckbill valves and pneumatic non-return valves. While there are many options out there, the process of selecting a safe, value-adding and durable water check valve can be made easy by getting in touch with an experienced valve manufacturer.