periphery of the diaphragm between the bonnet 1 and the valve body 4 provides an external static seal to prevent fluid leakage to the surrounding environment when the diaphragm sealed valve is in actual use the center portion and not the periphery of the diaphragm acts as a dynamic seal to prevent leakage or flow of liquid from valve inlet to outlet the invention proposes to accomplish an optimum external static seal this seal is different from the dynamic seal sought during the actual operation or activation of the diaphragm external static seal is usually achieved during the assembly of the diaphragm sealed valve in an external static seal the diaphragm is compressed to a point where liquid inside the valve does not leak to the surrounding environment here compression of the diaphragm is brought about by tightening of the fasteners used to connect the bonnet diaphragm and valve body together the tightening of the fasteners applies force or pressure to the bonnet and valve body which can be achieved for example by tightening the fasteners with a wrench which can be manually electrically or pneumatically driven fig2 shows the external static seal accomplished by compression of the peripheral areas of the diaphragm 2 between the bonnet 1 and valve body 4 caused by.