Abstract: The sealing ring is initially made with two arms which are oriented to define a fold. When in place between two overlapping pipes, the inwardly directed arm is rolled outwardly into coaxial relation with the unfolded arm in order to provide a tight seal between the two pipes. The seal ring may be initially formed with a U-shaped cross-section or with a cross-section in which one arm is disposed transverse to the other arm.

Abstract: The connecting piece is formed with a substantially flat planar flange to fit about a longitudinally extending slot in the rounded air conditioning duct. Due to the absence of any significant curvature of the duct in the area of the slot, the flat flange requires no rounding to conform to the curvilinear periphery of the air conditioning duct. The connecting piece also has a body of tapering shape which extends from the flange to a rounded connecting pipe.

Abstract: A machine for connecting workpieces, especially pipe bend segments or the like comprising a rotatable table for supporting the pipe bend segments which are to be interconnected and a working head having a pair of cooperating rolls for interconnecting contiguous ends of adjacent pipe bend segments, typically at abutting flanges, with one another. Adjustment means permit selectively changing the relative radial spacing between the working head and the rotatable table. Means coact with the rotatable table for elastically supporting the rotatable table in elevational position.