Double check valve for e.g. preventing back-flow of reduction agent from storage tank of exhaust gas after treatment system of internal combustion engine of motor car, has disk-like elastic membrane provided with two slots

摘要

The valve (10) has upper and lower valve chambers (14, 16) separated from each other by a disk-like elastic membrane (18). The membrane is provided with two slots (22, 24). A length of each slot is smaller than a diameter of the membrane. The slots cut in a region of a valve longitudinal axis (26). The membrane stays under pretension for increasing a sealing effect of the slots. The membrane includes a disk outside the slots. The disk is made of a metal alloy and/or fiber reinforced plastic material. The membrane is made of elastomer.