The non-return or check valves are devices that have the function of preventing the backflow of the fluid. The check valve is activated automatically by the pressure difference upstream and downstream of the shutter allowing the fluid to flow in one direction only. In this way it is possible to avoid contamination but also the emptying of the system in case of pump shutdown.
This type of valve is suitable for various applications in residential and industrial environments where the flow is required to flow in one direction only. We have, for example, non-return valves for sewers that protect against possible overload events, or non-return valves for air that allow compressed air to flow in only one direction.
Precisely to adapt in a functional way to the many applications, the non-return valve does not come in just one type. There are several models that differ in the mechanical structure.
The types of check valves are:
The material is also added to these differentiations. Depending on the applications, therefore on the type of fluids conveyed and the environment in which the valves are installed, it is possible to choose between 304 and 316 stainless steel, brass, cast iron and plastic.