Block valve, also called shutoff or on-off valve, is a type of valve designed to completely stop the flow of a fluid, such as a gas or liquid, through a pipeline. Its primary function is to create a tight, leak-proof seal when closed, allowing for the isolation of a section of the system for maintenance, repair, or safety purposes. When fully open, it permits the fluid to flow with minimal restriction and pressure loss. The term "block valve" is not a specific type of valve, but rather a functional description that can apply to various valve designs, including ball valves and gate valves, which are commonly used for this purpose due to their ability to provide full, unobstructed flow when open.
