Pneumatic Non-return Valve.
Non-return valves allow air to flow in one direction only. Pilot pressure is applied to port 1 of the valve which shifts the spring and ball mechanism so that air can pass through. Upon removal of pilot pressure to port 1, back pressure from port 2 pushes against the ball and spring mechanism stopping air from passing back through to port 1.
Non-return valves shown in this section are constructed of nickel plated brass. Port sizes offered are M5, G1/8, G1/4, G3/8 and G1/2 female threaded connections. An arrow on the valve shows the direction of flow.
Please click herer for further information.