Diaphragm valves have isolated stems and are suitable for applications moving gases, liquids, and suspended solids, such as slurries. They use an elastomer diaphragm to control and throttle the flow of chemically compatible media in a system. Manual-operated diaphragm valves for chemicals open and close with a handle, lever, or knob. They have wetted components (e.g., valve body, seals, seat) made from materials suited for compatible chemicals and corrosive media. Always refer to the manufacturer's Chemical Compatibility guide for more information. Pneumatically-operated diaphragm valves use compressed air to open and close the valve and control media flow. They have a high closing force for systems moving viscous liquids.