Check valves: swing check valves
Exotica Valves™ manufactures a unique line of check valves: Exotica CXK™. Check valves have a simple design, and in general cannot be manually operated. They are meant to prevent backflow, and come in swing, ball, piston, screw-down and dual-plate configurations. Among these, the swing check valve is the most widely used, in which the disc swings and closes against the seat in to prevent backflow.
Ball check and Piston Check valves
Ball-check and piston-check valves, whether spring-assisted or not, are used where it is not feasible to use a swinging disc design to prevent backflow, particularly in small diameters. The main difference between ball-checks and piston-checks is that the ball check obturator is ball shaped and the piston-check is conical shaped.
Dual-Plate Check valves
Dual-plate check valves are the preferred type of check valve when size and weight are a decisive factor when choosing a check valve.
Screw-down, Non-Return Check Valves (SDNR)
Screw-down, Non-Return Check valves are specially suited for applications where a combination of a globe and a check valve are required. The SDNR valve offers the functionality of a check valve with the option of manually creating a seal with a handwheel override that presses the disc toward the seat, even if the flow is not strong enough to do so.