Slide gate valves control or shut off the flow of bulk material through a chute, spout or pipe by means of a flat gate that slides perpendicular to the material flow path, either manually operated via a handle or lever, or automated using a pneumatic or electric actuator. In feed mills, slide gates are widely used beneath storage bins and hoppers, at conveyor transfer points, and anywhere flow needs to be reliably started, stopped or isolated.

Unlike diverter valves, which route material between multiple paths, slide gates are typically used simply to open or close a single flow path, making them a fundamental and widely used component for material isolation, batch control and equipment maintenance access throughout a feed mill.

Gate construction typically features a flat plate, often with a beveled or knife-edge leading edge, that travels within guide channels to shear through any material in its path as it closes, with the guide channel design and the clearance between gate and frame both affecting how cleanly the gate can seal once fully closed.

Manual slide gates remain common for infrequently operated applications or where automation cost is not justified, typically operated via a simple lever or threaded handwheel mechanism, while automated gates — driven pneumatically or electrically — are favored where frequent operation, remote control, or integration with a process control system is required.

Gate wear, seal condition and actuator function (where automated) are the main maintenance considerations; a slide gate that does not seal completely when closed can allow material to leak or "weep" through, which is particularly problematic where complete isolation is needed for safety, cleaning or batch separation purposes.

In applications involving particularly fine or free-flowing material, gate sealing performance can be a more demanding requirement than in applications handling coarser material, sometimes necessitating gates fitted with additional sealing strips or gaskets along the gate edges to achieve an adequately dust-tight or material-tight closure beyond what the bare metal-to-metal fit alone would provide.