An adjustable valve is a valve that can be adjusted to regulate the flow of fluid or gas through a pipe or conduit. It typically consists of a movable element that can be positioned to control the size of the opening through which the fluid or gas flows. Adjustable valves are commonly used in industrial and commercial applications for precise control of fluid or gas flow and may be manually or electronically operated. They may also have additional features such as flow meters, pressure gauges, or temperature sensors for improved monitoring and control.