A coupling assembly (80, 90, 600) for forming a joint between a first secondary pipe section (102, 122, 604) and a second secondary pipe section (102, 122, 614), and accommodating a primary joint therein, in a secondary containment system said coupling assembly comprising; a) a first coupling component (60, 130, 560, 601) having a first end (61, 131, 561, 602) and a second end (66, 136, 567, 605), 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 (62, 132, 603) having a first internal diameter adapted to form a sliding fit with said first secondary pipe section (102, 122, 604), 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 (67, 137, 567, 607) extending from the end face; b) a second coupling component (70, 140, 570, 611) having a first end (71, 141, 571, 612) and a second end (76, 146, 577, 615), 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 (72, 142, 613) having a first internal diameter adapted to form a sliding fit with said second secondary pipe section (102, 122, 614), 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 (77, 147, 577, 617) 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 (60, 130, 560, 601) having a first end (61, 131, 561, 602) and a second end (66, 136, 567, 605), 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 (62, 132, 603) having a first internal diameter adapted to form a sliding fit with said first secondary pipe section (102, 122, 604), 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 (67, 137, 567, 607) extending from the end face; b) a second coupling component (70, 140, 570, 611) having a first end (71, 141, 571, 612) and a second end (76, 146, 577, 615), 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 (72, 142, 613) having a first internal diameter adapted to form a sliding fit with said second secondary pipe section (102, 122, 614), 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 (77, 147, 577, 617) extending from the end face and adapted to be sealed in use to the mating region of the first coupling component.