In hydraulic engineering, a gate is a rotating or sliding structure, supported by hinges or by a rotating horizontal or vertical axis, that can be located at an extreme of a large pipe or canal in order to control the flow of water or any fluid from one side to the other. It is usually placed at the mouth of irrigation channels to avoid water loss or at the end of drainage channels to elude water entrance. Gate Valve When using a gate, one thing that is used in certain applications such as manufacturing, mining, and others is the gate valve. Fluids will run through the valve to help lubricate the moving parts of a machine, transmit power, close off openings to moving parts, and to assist evaporating the amount of heat coming through. These fluids will flow throughout the gate valve with little resistance to flow and there is additionally small drops in pressure. Within the gate valve, there is a gatelike disk that moves up and down perpendicular to the path of flow and seats against two seat faces to shut off flow. Best Uses Gate valves are ideal for services that require little valve operation and where the disk is kept either opened or closed. For the usual type of gate valves that are out there today in industry, close regulation of these parts is recommended, however, it is impossible to do so. The Velocity of the fluid against a partly opened disk may cause vibration and chattering which will ultimately lead to damage to the seating surfaces and this is a common way that gate valves fail. Type of Fluid When using a gate valve, one must consider the type of fluid to use in the machine. Since gate valves are used in so many different types of machines that are used in so many different environments for different kinds of applications, it is highly recommended to use a fluid with a high viscosity index because it is a great multi-purpose fluid. See also Sluice Valve References Hydraulic engineering