A tank assembly comprising an axis of elongation, wherein the tank assembly further comprising: • a tank cover extending along the axis of elongation of the tank assembly and formed with first set of channels (10a and 10b); a tank header comprising portions (20a and 20b) that in conjunction with the first set of channels (10a and 10b) formed on the tank cover are adapted to define a first manifold and a second manifold when the tank header and the tank cover are assembled with respect to each other, the tank header further comprising apertures (22a and 22b) configured on the respective portions (20a and 20b) thereof, wherein at least one of an intermediate plate and an end cover is orthogonally assembled with respect to longitudinal axis of the first and second manifolds (30a and 30b) to form a connection system , the connection system is formed with an inlet , an outlet and fluid flow passages (30c and 30d) configuring fluid communication between the inlet and the outlet (50a and 50b) and the respective first and second manifolds (30a and 30b), wherein the intermediate plate of rectangular configuration comprises: • a set of concave profiles and configured along a second side orthogonal to a first thereof; and • either one of tabs and notches formed on the sides thereof for configuring crimping connection with the heat exchanger core , the tank assembly being characterized in that the intermediate plate further comprises a first set of sleeves (62a and 62b) disposed along the first side being aligned to and adapted to receive and hold respective manifold inlet and outlet . • a tank cover extending along the axis of elongation of the tank assembly and formed with first set of channels (10a and 10b); a tank header comprising portions (20a and 20b) that in conjunction with the first set of channels (10a and 10b) formed on the tank cover are adapted to define a first manifold and a second manifold when the tank header and the tank cover are assembled with respect to each other, the tank header further comprising apertures (22a and 22b) configured on the respective portions (20a and 20b) thereof, wherein at least one of an intermediate plate and an end cover is orthogonally assembled with respect to longitudinal axis of the first and second manifolds (30a and 30b) to form a connection system , the connection system is formed with an inlet , an outlet and fluid flow passages (30c and 30d) configuring fluid communication between the inlet and the outlet (50a and 50b) and the respective first and second manifolds (30a and 30b), wherein the intermediate plate of rectangular configuration comprises: • a set of concave profiles and configured along a second side orthogonal to a first thereof; and • either one of tabs and notches formed on the sides thereof for configuring crimping connection with the heat exchanger core , the tank assembly being characterized in that the intermediate plate further comprises a first set of sleeves (62a and 62b) disposed along the first side being aligned to and adapted to receive and hold respective manifold inlet and outlet . • a set of concave profiles and configured along a second side orthogonal to a first thereof; and • either one of tabs and notches formed on the sides thereof for configuring crimping connection with the heat exchanger core , the tank assembly being characterized in that the intermediate plate further comprises a first set of sleeves (62a and 62b) disposed along the first side being aligned to and adapted to receive and hold respective manifold inlet and outlet . <EOS>