A coupling assembly for forming a joint between a first secondary pipe section and a second secondary pipe section , and accommodating a primary joint therein, in a secondary containment system said coupling assembly comprising; a) a first coupling component having a first end and a second end , said component having a longitudinal axis between the first end and the second end, the first end of the component including a first tubular portion having a first internal diameter adapted to form a sliding fit with said first secondary pipe section , and a first sealing means adapted such that the first end can be sealed in use to said first secondary pipe section; the second end having a second diameter or cross-sectional area of an opening in the second end which is larger than the first diameter or the cross-sectional area of an opening in the first end and wherein the second end incorporates an end face, wherein the end face is in a plane substantially non-perpendicular to the longitudinal axis of the component and wherein the second end further includes a mating region extending from the end face; b) a second coupling component having a first end and a second end , said component having a longitudinal axis between the first end and the second end, the first end of the component including a first tubular portion having a first internal diameter adapted to form a sliding fit with said second secondary pipe section , and a first sealing means adapted such that the first end can be sealed in use to said second secondary pipe section; the second end having a second diameter or cross-sectional area of an opening in the second end which is larger than the first diameter or the cross-sectional area of an opening in the first end and wherein the second end incorporates an end face, wherein the end face is in a plane substantially non-perpendicular to the longitudinal axis of the component and wherein the second end further includes a mating region extending from the end face and adapted to be sealed in use to the mating region of the first coupling component. a) a first coupling component having a first end and a second end , said component having a longitudinal axis between the first end and the second end, the first end of the component including a first tubular portion having a first internal diameter adapted to form a sliding fit with said first secondary pipe section , and a first sealing means adapted such that the first end can be sealed in use to said first secondary pipe section; the second end having a second diameter or cross-sectional area of an opening in the second end which is larger than the first diameter or the cross-sectional area of an opening in the first end and wherein the second end incorporates an end face, wherein the end face is in a plane substantially non-perpendicular to the longitudinal axis of the component and wherein the second end further includes a mating region extending from the end face; b) a second coupling component having a first end and a second end , said component having a longitudinal axis between the first end and the second end, the first end of the component including a first tubular portion having a first internal diameter adapted to form a sliding fit with said second secondary pipe section , and a first sealing means adapted such that the first end can be sealed in use to said second secondary pipe section; the second end having a second diameter or cross-sectional area of an opening in the second end which is larger than the first diameter or the cross-sectional area of an opening in the first end and wherein the second end incorporates an end face, wherein the end face is in a plane substantially non-perpendicular to the longitudinal axis of the component and wherein the second end further includes a mating region extending from the end face and adapted to be sealed in use to the mating region of the first coupling component. <EOS>