a plastic clamping ring for securing and sealing the joint between adjoining peripherally flanged ducts has a generally v - shaped cross - section provided with a molded in place or bonded seal which engages the flange rims . a latching feature permits the ends of the clamp to be temporarily latched in position to frictionally limit , without preventing , adjustment of the relative angular position of the two adjoining coaxial ducts prior to application of the full clamping force .