Abstract: A method is described for installing a stud to extend above a surface of a composite portion of a tank or other structure subject to the pressure of cryogenic fluid, so that another structure can be attached to the stud. The method includes drilling a through aperture at the location of the stud, and installing a threaded insert near the outer surface of the aperture, if not already installed. A metal bolt having a CTE less than that of the composite material is selected. The bolt has an unthreaded shank portion and a threaded portion. The length of the bolt exceeds the length of the projecting stud and the thickness of the composite. The bolt is assembled with a commercial k seal, a collar having a CTE much less than that of the bolt, and another k seal. The seals mate with corresponding frustoconical surfaces of the composite and of the collar, and when the bolt is properly torqued to a preload, prevent leakage.

Abstract: A method is described for installing a stud to extend above a surface of a composite portion of a tank or other structure subject to the pressure of cryogenic fluid, so that another structure can be attached to the stud. The method includes drilling a through aperture at the location of the stud, and installing a threaded insert near the outer surface of the aperture, if not already installed. A metal bolt having a CTE less than that of the composite material is selected. The bolt has an unthreaded shank portion and a threaded portion. The length of the bolt exceeds the length of the projecting stud and the thickness of the composite. The bolt is assembled with a commercial k seal, a collar having a CTE much less than that of the bolt, and another k seal. The seals mate with corresponding frustoconical surfaces of the composite and of the collar, and when the bolt is properly torqued to a preload, prevent leakage.

Abstract: A method is described for installing a stud to extend above a surface of a composite portion of a tank or other structure subject to the pressure of cryogenic fluid, so that another structure can be attached to the stud. The method includes drilling a through aperture at the location of the stud, and installing a threaded insert near the outer surface of the aperture, if not already installed. A metal bolt having a CTE less than that of the composite material is selected. The bolt has an unthreaded shank portion and a threaded portion. The length of the bolt exceeds the length of the projecting stud and the thickness of the composite. The bolt is assembled with a commercial k seal, a collar having a CTE much less than that of the bolt, and another k seal. The seals mate with corresponding frustoconical surfaces of the composite and of the collar, and when the bolt is properly torqued to a preload, prevent leakage.