Gate Valves, also known as knife valves are used when the fluid flow is to be controlled. Gate valves are used for linear motion flow and are equipped with a flat closure element that slides into the stream and shuts the flow. They are one of the most commonly used valves.
Gate valves can cut through slurries, and other viscous materials such as heavy oil, grease, molasses, varnish, heavy cream and more. They come in a variety of sizes to cater different volume of flow. These are not used under low pressure limitations. However, they can be used for throttling purposes but, excessive use for throttling can cause the disc and seat of gate valve to erode.
Gate valves are best suited for conditions where infrequent use of valves is required. They are designed to drop the pressure across the valve when it is fully opened and then stop the flow completely.