Tube sheet comprising two interspaced sheet members and heat exchanger comprising at least one such tube sheet

Claim 1

A header assembly for a heat exchanger including two spaced tube sheet members provided with at least one pair of aligned bores therethrough, a tube section extending through each pair of aligned bores, and a sleeve surrounding each tube section in the space between the sheet members, the sleeve being sealed to both sheet members and both ends of the sleeve being sealed to the exterior of said tube section, the internal surface of the sleeve being spaced from the external surface of the tube section to provide an internal chamber therebetween, and the sleeve wall having at least one opening intermediate the ends of the sleeve for communicating the internal chamber with the space between the sheet members, wherein the improvement comprises at least one end of said sleeve extending through the bore in the corresponding sheet member, said one end being sealingly attached to the exterior of said tube section at a location spaced from said sheet member on the side opposite the space between the sheet members, whereby said internal chamber extends beyond at least one of the sheet members to avoid warping during assembly.