An industrial non-return valve, also known as a check valve or one-way valve, is a mechanical device designed to allow fluid or gas to flow in one direction only. Its primary function is to prevent backflow, which is the reverse flow of fluids in a piping system. This is crucial in various industrial applications to ensure the safety and efficiency of the process.

The design of a non-return valve is relatively simple. It typically consists of a valve body with an inlet and outlet, and a movable mechanism that opens or closes the flow path based on the direction of the fluid. The valve allows fluid or gas to flow forward (in the intended direction) while automatically closing to block any reverse flow or backflow. When the fluid attempts to flow in the opposite direction, the mechanism inside the valve, such as a spring or a hinged disc, creates a sealing action, preventing the backflow.