Pipe coupling

A pipe joint, comprising:

• a first pipe comprising a first flange;
• a second pipe comprising a second flange;
• a first sleeve installed within the first pipe;
• a second sleeve installed within the second pipe;
• a one piece annular ring positioned between and in direct contact with the flange of the first pipe and the flange of the second pipe, wherein the annular ring comprises a first rectangular hub that extends into the first pipe substantially parallel with the first pipe and a second rectangular hub that extends into the second pipe substantially parallel with the second pipe;
• a plurality of threaded fasteners installed through the flange of the first pipe, through an opening extending longitudinally within the annular ring, and through the flange of the second pipe, wherein the plurality of threaded fasteners secure and compress the annular ring between the flange of the first pipe and the flange of the second pipe;
• a first complementary engagement structure comprising a first complementary feature extending from an end surface of one of the hub or first sleeve and a second complementary feature extending from an end surface of the other of the hub or first sleeve, wherein the first and second complementary features are substantially parallel with the first sleeve, and wherein the first complementary engagement structure provides a first seal interface within the pipe joint;
• and
• a second complementary engagement structure comprising a first complementary feature extending from an end surface of one of the hub or second sleeve and a second complementary feature extending from an end surface of the other of the hub or second sleeve, wherein the first and second complementary features are substantially parallel with the second sleeve, and wherein the second complementary engagement structure provides a second seal interface within the pipe joint.