Removable stud for joining casing flanges

A flange connection for connecting together a pair of casing end flanges of a pair of end-to-end, axisymmetric tubular casings, said connection comprising:

• a) a first casing having at least a first end flange that extends substantially radially outwardly relative to the first casing, and a second casing having at least a second end flange that extends substantially radially inwardly relative to the second casing and that is engageable with the first end flange, wherein the end flanges each include a plurality of circumferentially-spaced apertures and wherein corresponding apertures of the respective flanges are substantially coaxially aligned;
• b) a stud extending through a pair of aligned flange apertures and including a stud shank, wherein one end of the stud is threadedly received within one of the aligned apertures and the other end of the stud extends outwardly of the other aligned flange aperture and is engaged by a connecting nut to hold the pair of flanges in face-to-face relationship;
• c) an external formation carried by the stud in an inner region between end threads and extending radially outwardly from the stud, the external formation having a peripheral surface;
• and
• d) an anti-rotation member that is adapted to be engageable with the peripheral surface of the external formation to prevent unintended rotation of the stud relative to the casing end flanges.