What are the spring type non return check valves used for?

Spring type non return check valves are used to control the flow of fluids or gases in a piping system, and specifically to prevent backflow of these substances. These valves operate by using a spring to keep a disc or ball in a normally closed position, preventing the fluid or gas from flowing in the opposite direction. When fluid or gas flows in the forward direction, it overcomes the spring pressure and opens the valve, allowing it to pass through. When the flow stops or reverses, the spring immediately pushes the disc or ball back into the closed position, preventing any backflow.

Spring type non return check valves are commonly used in a variety of industries, including plumbing, water treatment, chemical processing, oil and gas, and many others. They are particularly useful in applications where preventing backflow is critical, such as in sewage systems, water supply lines, and medical equipment. They are also frequently used in pumps, compressors, and other machinery to protect against damage caused by backflow.