The Brand, full range pressure compensating variable flow control is designed so that the orifice area varies as the lever is rotated. Fluid travels past the variable orifice, through the compensator spool and then out the controlled flow port. Therefore the flow out of the CF port is proportional to the orifice area which can vary from closed to open. The sum of the controlled flow and the excess flow equals the inlet flow and as the controlled flow increases the excess flow decreases. Both outlet flows are pressure compensated with a spool that maintains a constant flow by adjusting for pressure. Hunting between the compensated pump and our valve is dampened with a dashpot on the compensator spool. Thus, the outlet flow is smooth and constant regardless of the pressure on the CF and EX port. External seals on the rotary spool prevent contamination from getting between the spool and the casting, thus preventing the spool from locking in one position. All FC’s are built with stainless steel (416) rotary spools to help prevent the rotary spools from locking up when they are in a corrosive environment. We also offer the FC with outlet ports coming from the top of the casting.
The adjustable ball spring relief (R) and the adjustable high lift ball spring relief (B) allow the customer pressure compensated flow up to the pressure setting on the relief. Once the pressure on the CF port increases above the relief setting the relief valve opens and diverts flow to the EX port while maintaining the pressure on the CF port. The EX port must be plumbed back to tank for both of these reliefs. Both relief options are preset to 1500 psi (103 bar), standard, and field adjustable from 750 to 3000 psi.(52 to 207 bar). Pressure settings between 250 and 750 psi (17 and 52 bar) can be achieved by using a different spring. The B option’s advantage over the R option is that the cracking pressure at low and high flow is virtually the same. The B option is also more stable when flow is traveling past the ball and spring.
The free reverse flow (55) option is designed primarily where cylinders and motors are needed to go in reverse. Flow can go in reverse from either the EX or the CF port to the inlet. Flow is not metered when it goes in reverse. The non-metered flow travels past the poppet, down the center of the valve, past the compensator spool and through the inlet. The steel poppet seat inside the free
reverse flow check is heat treated to assure a long life.