In a storage tank having at least a fixed exterior roof through which a pipe connection extends for feeding or removing a fluid from the tank, the improvement comprising a pipe connection including a pipe extending through an oversized hole in the roof; a sleeve, surrounding but spaced outwardly from the pipe, extending through the roof hole and connected to the roof around the hole; the sleeve having an upper end spaced upwardly above the roof and connected to the pipe; the sleeve having a lower end spaced below the roof and unattached to the pipe; granular insulation occupying the space between the sleeve and the pipe; and a barrier preventing the granular insulation from flowing out the sleeve lower end.