FC51 Series 3-Port Pressure Compensated Priority Flow Control Valve 0-50 GPM Flow Range

Yes, this is a 3-port pressure compensated priority flow control valve.

Yes, it'll maintain priority flow up to the full 50 GPM rating while compensating for pressure variations. The pressure compensation feature keeps your priority circuit getting consistent flow even when system pressure fluctuates, so whatever equipment you've got on that priority line will keep running at the flow rate you set.