Pressure-reducing apparatus

A gas-pressure reducing apparatus comprising a casing having a gas inlet connection and a gas outlet connection, a cover mounted upon said casing, a manometric membrane mounted between the casing and the cover and comprising two faces subjected to the pressure of the gas to be controlled and to the action of an adjustment spring respectively, abutment means extending from said cover towards the interior of the apparatus and onto which the membrane is adapted to bear and pivot, the position of said abutment means being such that it divides the membrane into two unequal surfaces comprising a relatively large surface subjected to the action of said adjustment spring and a relatively small surface adapted to close the gas inlet into the casing of the apparatus, wherein said casing is provided with one stop member extending therefrom and directed towards the membrane at a position located below, and substantially aligned with, said abutment means so as to positively prevent said membrane from closing said gas inlet connection when the membrane is collapsed under the action of said spring within the casing of the apparatus.