Pump diaphragm is a flexible, membrane-like material that is used to help move liquid or gaseous fluids in a pump. It functions by transferring force from the pump’s drive mechanism to the fluid. The diaphragm is usually made out of rubber, plastic, or metal. It is typically dome-shaped and placed between two chambers of the pump. Fluid is pumped when the diaphragm is moved from one side of the chamber to the other by the drive mechanism, creating a suction that pulls the fluid into the pump and a subsequent pressure that pushes it out.