System for closing a device for the low-pressure dispensing of a pasty liquid material

The invention relates to a device (1) for dispensing a pasty liquid material (2) by means of a low-pressure manual metering pump (5), which is provided with an system for closing an end (32), and which is intended for a rigid or flexible container (4), the operation of said pump being ensured by: a lower check valve (11) and a metering chamber (10) which consists of a resiliently deformable bellows (9) and which is in communication with an upper valve (14) consisting of, in series: a stopper (16) for the channel (13) of the spout (8), which ensures that the end (32) is closed; a resiliently deformable diaphragm (15) enabling the stopper (16) to be opened; an auxiliary return member (17) suitable for the low pressures causing the closing of the stopper (16); and a sealed vessel (18), characterized in that the resiliently deformable diaphragm (15) is combined with the vessel (18) that said diaphragm seals, wherein the auxiliary return member (17) is arranged inside said vessel so as to be permanently linked to the diaphragm (15), and said vessel includes two levels (19, 20) that are resiliently deformable according to various characteristics.