Gate valves are most commonly used in industrial piping to isolate flow rather than regulating it. They are used as stop valves to fully shut off or fully turn on flow, which is the only job gate valves are recommended for. Flow moves in a straight line and practically without resistance when the wedge is fully raised.
Seating is perpendicular to the line of flow, which is one reason why gate valves are impractical for throttling service and for frequent operation. Repeated movement of the wedge near the point of closure under high-velocity flow may create drag on the seating surfaces and cause galling or scoring on the downstream side. A slightly opened wedge may cause turbulent flow with vibration and chattering of the wedge.
Gate valves usually require more turns to fully open. Also, unlike many globe valves, the volume of flow through the valve does not directly relate to the number of turns of the hand wheel.
Since most gate valves have a wedge with matching tapered seats refacing or repairing of the seating faces is not a simple operation.
Gate valves, while not designed for throttling or too-frequent operation are generally ideal for services requiring full flow or no flow.