Gravity flow system valve The Schenck Process 2-Way and 3-Way ‘Y’ Valves are available in manual or air-operated platforms and are used in gravity flow systems. Both the manual and air-operated diverters come equipped with square, flanged inlet and outlet ports. The 2-Way ‘Y’ Valve is designed to divert product flow in gravity systems from one source into two destinations. The valve has one straight through leg and a second leg to divert product flow at