Abstract: Apparatus for introducing air (3) into a hydropneumatic reservoir (1) connected to pipework (2) comprising a sensor (6) of the pressure in the reservoir, a valve (9) controlled by a signal from the sensor and opening into the open air on one side, a tube (8) connected at one end to the valve and at the opposite end to the pipework (2), a first check valve (11) arranged in the tube to prevent liquid from travelling towards the open air, and a second check valve (5) arranged in the pipework between the reservoir (1) and the tube (8), the second check valve (5) being in the closed state when the pressure in the pipework (2) on the side nearest the tube (8) is less than the pressure in the reservoir (1).

Abstract: Apparatus for introducing air (3) into a hydropneumatic reservoir (1) connected to pipework (2) comprising a sensor (6) of the pressure in the reservoir, a valve (9) controlled by a signal from the sensor and opening into the open air on one side, a tube (8) connected at one end to the valve and at the opposite end to the pipework (2), a first check valve (11) arranged in the tube to prevent liquid from travelling towards the open air, and a second check valve (5) arranged in the pipework between the reservoir (1) and the tube (8), the second check valve (5) being in the closed state when the pressure in the pipework (2) on the side nearest the tube (8) is less than the pressure in the reservoir (1).

Abstract: Device 7 for introducing air into a hydraulic system comprising a hydro-pneumatic reservoir 3 mounted on a pipe 1. The air introduction device 7 is mounted in such fashion as to introduce air into an area of the system containing water in which the pressure P.sub.s is either below or slightly above atmospheric pressure. The device is active when a lack of air is to be made good in the hydro-pneumatic reservoir 3.

Abstract: An air regulation system for a hydropneumatic reservoir of a hydraulic conduit includes a chamber, a water filling device for the chamber, a water emptying device for the chamber, an automatic air introduction device for introduction of air in the chamber during emptying, an automatic injection device for injecting air from the chamber to the reservoir during filling, and a control device connected to at least one excess sensor for sensing the overpassing of a threshold level of water contained in the reservoir and also connected to a chamber filling and emptying assembly. If the sensor indicates an insufficient air volume in the reservoir, the control device initiates chamber filling/emptying cycles until the sensor indicates that the air volume in the reservoir is sufficient.