Safety Connecting Device, In Particular For Piping, An End-Coupler For Such Device, And A Method For Manufacturing A Nut Therefor

A device for connecting first and second sections of a piping, comprising:

• a first end-coupler couplable with the first piping section,
• a second end-coupler couplable with the second piping section, and
• a nut provided at a first end with a threaded bore,
• wherein the second end-coupler is received in the nut and the first end-coupler is screwed along a longitudinal axis up to a tightening position wherein the first end-coupler is in axial stress with the second end-coupler,
• the nut and the second end-coupler including respective axial bearing means to limit the axial displacement of the nut with respect to the second end-coupler in the nut screwing direction,
• the nut and both end-couplers each comprise a tubular body which undergoes the axial stress,
• one of the first or second end-couplers and the nut defining respective mutual blocking elements comprising anti-rotation means including at least one protrusion on one of the blocking elements and at least one recess on the other blocking element,
• the at least one protrusion able to radially elastically penetrate the at least one recess during a relative rotation between the nut and the blocking end-coupler, and to come out therefrom when a torque exceeding a determined threshold is applied to the nut,
• wherein the at least one protrusion extends from at least one elastic tab which is formed in the material of the tubular body of one of the blocking elements.