A priority flow control takes one pump flow and guarantees a set amount to the priority function first, sending whatever is left over to the secondary circuit. Steering is the classic case: the steering orbital always gets its flow, and the implement gets the remainder.

The FC51 is the lever adjusted version — a cast iron body with a large handle so the operator can change the priority flow on the fly without tools. The FCR variants add an integral relief valve on the priority port.

Watch the excess flow. Whatever the priority circuit does not take goes out the excess port — at pressure. That port must go somewhere useful or straight back to tank; dead-heading it will heat the oil fast.

Manufactured by CBF Hydraulic, Montecchio Maggiore, Italy.