Multi layer priming pump

The priming pump consists of an envelope with an elastically deformable central zone (1) linked to two connecting zones (2) and comprising an outer layer (3) of an elastomer and an inner layer (4) that forms a barrier for the fluid inside the pump. The envelope can also have an intermediate layer connecting the outer and inner layers. The outer layer is between 0.1 and 2 mm thick, while the inner layer is 0.1 - 1 mm thick.