Check valve mounted on the ends of the KEITH RUNNING FLOOR II (KRFII) cylinders.
The plunger will be pushed and opens the port for the next cylinder
The KRFII drive has four equal check valves (CKV) and can be interchanged.
Two CKV on the load end of cyl #1 and #2 and two on the unload side on cyl #2 and #3.
The non-DX CKV have the tubes connected by clamping and used until 01/2009.