Abstract: An improved fluid expulsion device of the class comprising an expulsion container containing a diaphragm adapted to be displaced by a pressure fluid acting on one side of the diaphragm to expel a second fluid at the opposite side of the diaphragm. The diaphragm is bonded to the inner container wall, either by electrodeposition of a metal on the wall in such a way as to form the diaphragm on and in bonded relation to the wall or by adhesively bonding a preformed diaphragm to the wall by adhesive bands, whereby displacement of the diaphragm is accompanied by peeling of the latter from the container wall without wrinkling, tearing, or ripping.