| 摘要 |
The present invention relates to a nonreturn device (1) for a pipe (2) for carrying a fluid, comprising - a shutoff valve (3) provided with actuating means (5) comprising a device (54) for accumulating/releasing potential energy, - a nonreturn valve (6) designed to maintain a pressure difference ΔP between its inlet (6a) and its outlet (6b), and - a triggering piston (8), the internal volume (82) of which is divided into two chambers (82a, 82b) by a mobile element (83) which is equipped with an activation rod (84); said first and second chambers (82b and 82a) are in fluidic communication with said pipe (2), respectively upstream and downstream of said nonreturn valve (6); and the activation rod (84) of the triggering piston (8) is designed to be able to actuate said shutoff valve (3) in order to move it from its inactive (open) position into its active (closed) position if said pressure difference ΔP drops below a predetermined threshold value, with the release of the potential energy accumulated in said device (54). |
