In mechanics, a diaphragm is a sheet of a semi-flexible material anchored at its periphery and most often round in shape. A diaphragm pump uses a diaphragm to pump a fluid. A typical design is to have air on one side constantly vary in pressure, with fluid on the other side. For more details download the CAD file from our cadbull website. This can be used by architects and engineers. Download this 2d AutoCAD drawing file.