Adapter coupling

An adapter coupling for joining a flanged pipe element to a grooved pipe element, said adapter coupling comprising:

• a plurality of segments attached to one another end to end surrounding a central space and a longitudinal axis, each of said segments comprising:
• a flange body having a pipe-facing side portion and a flange-facing side portion, said flange body having facing surfaces at each end of said segments;
• a key positioned on said flange body, said key extending toward said central space;
• and
• projections extending from said pipe-facing side portion at each end of said segments, said projections extending in a direction parallel or generally parallel to said longitudinal axis, each of said projections comprising:
• an opening configured to receive a fastener, said opening being positioned between said central space and an outermost surface of said flange body,
• wherein said facing surfaces on respective ends of said segments are in facing relation with one another and are configured to be drawn toward one another as said fasteners are tightened.

In combination, an adapter coupling and a grooved pipe element, said adapter coupling comprising:

• a plurality of segments attached to one another end to end surrounding a central space, each of said segments comprising:
• a flange body having a pipe-facing side portion and a flange-facing side portion;
• a channel positioned within said flange body extending circumferentially therearound and facing said central space;
• a gasket positioned in said channel;
• a key positioned on said flange body, said key extending toward said central space, said key comprising:
• a radially inwardmost tip surface extending along said key,
• a first keywall extending from said flange body to said tip surface, and
• a second keywall extending from said flange body to said tip surface,
• wherein said first keywall and said second keywall are inclined towards one another, being closer together at said tip surface;
• and
• adjustable attachment members positioned at ends of said segments for attaching said segments to one another;
• said grooved pipe element comprising:
• a sidewall surrounding a longitudinal axis and defining a bore, said sidewall having an outer surface;
• an endform;
• and
• a tubular portion connected to said endform, wherein said endform extends from an end of said grooved pipe element to said tubular portion, wherein said endform comprises:
• a groove defined by said outer surface, said groove extending circumferentially around said bore, said groove comprising:
• a first groove side surface,
• a second groove side surface facing said first groove side surface and in spaced apart relation from said first groove side surface along said longitudinal axis, wherein said first groove side surface is positioned between said end of said grooved pipe element and said second groove side surface, and
• a floor surface contiguous with said first groove side surface and said second groove side surface,
• wherein said keys are configured to engage with said groove such that said first keywall is configured to engage with said first groove side surface and said second keywall is configured to engage with said second groove side surface.

A method of joining a flanged pipe element to a grooved pipe element using an adapter coupling, said adapter coupling comprising a plurality of segments attached to one another end to end in a preassembled state surrounding a central space, each of said segments comprising a flange body, a channel positioned within said flange body, a gasket positioned in said channel, a key positioned on said flange body extending toward said central space, said key comprising a tip surface, a first keywall, and a second keywall, and adjustable attachment members positioned at ends of said segments;

• said grooved pipe element comprising a sidewall having an outer surface, an endform comprising a groove defined by said outer surface, said groove comprising a first groove side surface, a second groove side surface, and a floor surface;
• said method comprising:
• inserting said grooved pipe element into said central space of said adapter coupling in said preassembled state;
• adjusting said adjustable attachment members to draw said plurality of segments toward one another such that said first keywall engages said first groove side surface and said second keywall engages said second groove side surface;
• and
• joining said flanged pipe element to said adapter coupling by aligning holes in said flanged pipe element with flange holes in said segments and securing with fasteners.