20 the receiver posts 32 can be adjusted so as to dispose pairs of receiver posts in mutually cooperating positions in which their cavities 33 mate to define a groove for receiving the bend of a tube t different pairs of receiving posts 32 can be disposed in different mutually cooperating positions as needed to accommodate different patterns of the bends of the hairpin tubes t by making the base means 31 of a plurality of plates 31a 31b and 31c an entire row of receiver posts 32 can be removed as a unit if that row of receiver posts is not to be used and it would interfere with the end sheet of a heat exchanger when the end sheet is flat it is not necessary to remove unused receiver posts 32 receiver posts 32 made for use with one size of tubing such as 3 8 inch od tubing can be interchanged with receiver posts that accommodate a different size of tubing such as 5 16 inch 0d tubing if the pattern for center distance and row to row dimension remain the same fig5 and 6 illustrate modifications in which the receiver post 32 is removably mounted on an intermediate support 46 or 46a which in turn is attached to the base plate here the base plate 31a in the embodiment of fig5 a pull dowel 47 is press fit into a blind ended vertical hole 48 in the lower end of the receiver post 32 the dowel 47 slidably extends into a vertical central opening 49 in the upper end of the intermediate support 46 a roll pin 51 is press fit into a laterally offset opening 52 in the receiver post 32 and.