LOW TEMPERATURE LIQUID STORAGE TANK OF THE INTERNAL HEAT INSULATING TYPE HAVING CRACK DETECTING MEANS

摘要

Low temperature liquid storage tank of the internal heat insulating type having crack detecting means. The tank is provided with a primary impermeable layer located on the inner wall of the tank shell with a heat insulating layer interposed therebetween. A second impermeable layer is provided in the interior of the heat insulating layer. A layer of gas permeable sheet material is provided on the low temperature side of the secondary impermeable layer as well as on the high temperature side of the secondary impermeable layer and a circulating gas feed pump and a gas analyzing device are connected through connecting lines to the layer of gas permeable sheet material at the low temperature side of the secondary impermeable layer as well as to the layer of gas permeable sheet material at the high temperature side of the secondary impermeable layer, so that leakage of the low temperature liquid in the tank through possible cracks in the impermeable layers is detected by the circulating gas fed to the gas analyzing device by the pump through the layer of gas permeable sheet material.