A blow-moulding installation (10) for fabricating a container from a blank (12), includes a mould (20) which bounds a moulding cavity (18) in which a blank (12) is arranged, emerging through an opening of the mould (20), a tubular blowing nozzle (28) slidingly mounted between a raised rest position, and a lowered blowing position, in which the nozzle (28) is suitable for conveying a pressurized fluid into the blank (12), at least one element (46a) for locking the nozzle (28) in its lowered blowing position, the locking element (46a) being such as a lock (46a) including a strike (48a) and a movable bolt (58a) which is elastically returned to a locking position in the strike.