Valves with Pilot Assist: Large size or high capacity, and high ratio valves are not what necessarily work the best. Good flow modulation (controlled “flow gain”) is a major consideration for valve selection. Designs that have short piston travel, where small incremental movements make large changes in metering areas, have “high gain”. Greater piston travel for incremental flow opening changes, result in “lower gain”, which usually proves to be best in most applications. The ability to choose between multiple pilot ratios and flow gains is a very desirable feature.