An LNG tank as disclosed can include an inner shell of stainless steel and an outer shell spaced at a distance from the inner shell, the inner and outer shells defining an isolation space therebetween. A double-walled pipe of stainless steel connected to the LNG tank can include an inner pipe. The outer wall of the pipe can be connected to the inner shell by a bellows-like pipe fitting welded to the outer wall of the pipe(s) and to the inner shell of the tank. The inner pipe for extending into a tank room can be connected to a valve in a valve block, and the outer wall of the pipe extending into the tank room can be welded to the valve block to provide a continuous secondary barrier for the inner pipe between the inner shell of the tank and the valve block.