An angle seat valve is a type of pneumatic valve used to control the flow of fluids in a variety of applications. It consists of a valve body with an angled seating surface, a spindle, and a piston or diaphragm actuator. The spindle controls the flow of fluid through the valve by moving the piston or diaphragm, which opens or closes the valve. Angle seat valve are commonly used in steam, water, and air applications, and are particularly useful in high temperature and high pressure environments. They are known for high flow rates, reliable operation, and ease of maintenance.