Gate valves are mechanical valves used to control pipeline fluid flow. They have a gate that may be raised or lowered to permit or prohibit fluid passage. The gate is often rectangular or wedge-shaped. Unrestricted fluid passage is made possible by the gate lifting out of the flow stream when it is open. The gate is lowered when closed, completely blocking the flow. Applications including water and wastewater systems, oil and gas pipelines, and industrial processes that demand straight-line flow control with little pressure loss frequently employ gate valves. They come in a variety of designs to suit different demands and may be operated mechanically or manually.

Gate valves are measured using numerous essential factors, such as nominal diameter (size), pressure rating, end connections, total length, and face-to-face dimension. The nominal diameter provides the valve's size in inches or millimeters, whereas the pressure rating shows the maximum working pressure. The way the valve attaches to the pipeline is determined by its end connectors, which might be flanged, threaded, or socket-welded. The total length and face-to-face measurement define the valve's physical dimensions, which are critical for installation and compliance with the piping system. In addition, the construction material is assessed to guarantee compatibility with the application's fluid, temperature, and pressure requirements.