The diaphragm valve is a flow control device that uses a flexible diaphragm to regulate the opening and closing of the fluid passage. This diaphragm, made of synthetic material, moves in response to changes in the position of the control lever. When the diaphragm expands, it allows fluid to pass through the valve, while closing it blocks the flow.

The function of the diaphragm valve is to gently control the discharge of free-flowing powders, granules and pellets, including chemicals, food and dairy products, pharmaceuticals, minerals and plastics, in gravity flow applications.

The diaphragm valve consists of a metal valve body enclosing two concentric rings, connected by a flexible sleeve. One end of the sleeve is fixed inside the valve body. The other end is attached to a control ring manipulated by an external lever. When the lever is rotated, the sleeve is twisted to the point that it becomes a solid, flat, compact barrier.