Pipe coupling having double-threaded tightening fastener and associated methods

A pipe coupling for coupling two pipe ends together, comprising:

• a sleeve having a generally cylindrical body portion with open opposing ends configured to receive the two pipe ends;
• a sealing gasket operatively coupled with the sleeve for engaging at least one of the two pipe ends;
• and
• a clamping element operatively coupled with the sleeve for compressing the sealing gasket into tightened engagement with at least one of the two pipe ends, the clamping element further including:
• first and second bolt flanges nominally spaced from one another to define a gap therebetween,
• a double threaded fastening bolt extending generally tangential to the generally cylindrical body portion of the sleeve and through the first and second bolt flanges, the fastening bolt including first and second external threaded portions connected at a central bolt portion and respectively defining a right-hand thread and a left-hand thread, and
• first and second fastening nuts in threaded engagement with the first and second external threaded portions of the fastening bolt and positioned to abut the respective first and second bolt flanges, the first fastening nut including a threaded bore with a right-hand thread and the second fastening nut including a threaded bore with a left-hand thread,
• wherein the fastening bolt further comprises:
• a removable head portion coupled with one of the first and second external threaded portions.

A method of connecting pipe ends together with a pipe coupling including a sleeve having a generally cylindrical body portion with open opposing ends, a sealing gasket, and a clamping element including first and second bolt flanges, a double threaded fastening bolt, and first and second fastening nuts, the method comprising:

• positioning the sealing gasket adjacent one of the open opposing ends of the sleeve;
• inserting a pipe end into the one open opposing end of the sleeve such that the sealing gasket and a portion of the sleeve surrounds the pipe end;
• engaging the clamping element with the one open opposing end of the sleeve and the sealing gasket such that the clamping element is operatively coupled with the sleeve, with the first and second bolt flanges nominally spaced from one another by a gap;
• inserting the fastening bolt to extend through the first and second bolt flanges in a direction generally orthogonal to the generally cylindrical body portion of the sleeve, with the first and second fastening nuts threadably engaged with first and second external threaded portions of the fastening bolt which define a right-hand thread and a left-hand thread, and with the first and second fastening nuts positioned to abut the first and second bolt flanges;
• and
• rotating the fastening bolt in a first direction to cause the first and second fastening nuts to move along the corresponding first and second external threaded portions towards one another, thereby drawing the first and second bolt flanges towards one another to shrink the gap and compress the sealing gasket and the sleeve into tighter engagement with the pipe end,
• wherein each of the first and second bolt flanges defines a socket with an arcuate surface, each of the first and second fastening nuts includes an arcuate surface, the arcuate surfaces defining corresponding features configured to prevent relative rotation, and the method further comprises:
• engaging the corresponding features of the first and second bolt flanges and the first and second fastening nuts, by inserting the first and second fastening nuts into the sockets of the first and second bolt flanges such that the arcuate surfaces of the first and second fastening nuts are brought into abutting engagement with the arcuate surfaces of the first and second bolt flanges, to thereby prevent rotation of the first and second fastening nuts relative to the first and second bolt flanges when the first and second fastening nuts are in abutting engagement with the first and second bolt flanges.