The diaphragm can be actuated manually or automatically, utilizing electric, hydraulic or pneumatic engagement methods. penumatic diaphragm valve are among the most commonly used automated diaphragm valves, as they only require the use of compressed air to expand and contract the diaphragm materials. Taking a look at the actual construction and operation of a diaphragm valve, it is easy to see why the rubbery durability and resilience of these materials is so integral. The cylindrical or spherical valve body, which houses the diaphragm and actuation device, is placed within a tank, tubing or piping system. Located at the bottom of the cylinder, the diaphragm is thick in the middle and thinner at the edges to allow for easy stretching. When the valve is open, the diaphragm is lifted up allowing fluids or gases to pass. When the valve is closed, the actuator engages a rod or piston known as the stem. This stem applies pressure to the diaphragm, pushing it towards the opposite wall of the piping. Each valve has two or more ports. Materials flow in through one port and out the other when the valve is not engaged. When an actuator is used to stretch the membrane of the valve, however, flow is limited or completely inhibited. The adaptability of the elastomeric material means it can be pulled and pressed over and over again without fail and can conform to the valve opening for a leak-proof seal.