Abstract: A band clamp is disclosed for making a joint in each of two pairs of closely spaced pipes wherein the pipes in each pair are aligned with each other. The clamp has a single closed loop clamp band for connecting adjoining ends of the first pair to make a sealed joint and connecting the adjoining ends of the second pair of pipes to make a sealed joint. The clamp band encircles both pairs of pipes and overlaps a portion of the adjoining ends of both pairs of pipes. The closed loop of the clamp band has oppositely disposed concave lobe portions spanning the gap between the pipes and a clamping mechanism is provided for drawing the lobe portions toward each other for tightening the band around the adjoining ends of the pipes to provide a mechanical connection and a sealed joint in each pair of pipes.

Abstract: A band clamp for pipe joints is disclosed comprising a band with confronting sidewalls when wrapped around pipes to be coupled. The clamping mechanism includes a pair of force bars outboard of the sidewalls and a spline with concave surfaces on opposite sides, the spline being disposed between the end flanges. A bolt extends through bolt holes and draws the flanges against the spline to stretch the band around the pipes when the bolt is tightened against the force bars. The sidewalls have lateral flanges which overhang the spline to arrest movement of the sidewalls relative to the spline to obtain alignment of the bolt holes when the clamp is tightened. In some embodiments, the band is folded back on itself to form a double thickness which extends from the upper end of each sidewall to a point beyond the lower end of the sidewall and provides an inverted flap sandwiched between the clamp band and the pipe. The inverted flap may be secured to the band by mechanical interlock between the layers.

Abstract: A pipe lap joint is disclosed with an improved sealing zone structure in the overlap region of the pipes. The sealing zone comprises a slot extending from the end of the outer pipe to an inner end wall of the slot. The joint comprises a band clamp with a clamping band which covers the sealing zone including the inner end of the slot. The slot has a bridge extending between the sidewalls and dividing the slot into an outboard slot segment and an inboard slot segment. The bridge has an axial dimension which is substantially smaller than the axial length of either of the slot segments. When the band clamp is tightened, the sealing zone is collapsed by collapse of the slot and consequent deformation of the bridge such that it obstructs fluid flow between the slot segments.

Abstract: A pipe lap joint is disclosed with an improved sealing zone and which comprises a pair of end-to-end intersecting slots in the outer pipe which allow the sealing zone to be collapsed against the inner pipe by a band clamp around the outer pipe. The outboard slot extends inwardly from the end of the pipe and the inboard slot is circumferentially offset and extends inwardly from the outboard slot. A frangible bridging segment of the wall of the pipe extends between the adjacent walls of the two slots and is deformed or fractured and maintains isolation between the slots when the pipe is collapsed. To facilitate collapse of the outer pipe, the length of the inboard slot is maximized for increased leverage of the clamping force.