| 摘要 |
PURPOSE:To keep pressure in a cold insulating layer of a low temperature tank always adjustable to a constant pressure by sealing gas storage chambers with a sealing member, and adjusting gas pressure in the cold insulating layer by moving a floating roof up or down. CONSTITUTION:When pressure in the cold insulating layer of a low temperature tank fluctuates, gas comes through a supply and exhaust pipe 18 into and out of a gas storage chamber 14, with increase and decrease of gas volume in the gas storage chamber 14, the gas storage chamber 17 is sealed air-tightly by sealing members 16; a floating roof 13 is moved up and down, and gas pressure in the cold insulating layer is adjusted to be a set pressure. Since this set pressure is held constant without positioning the floating roof 13, the pressure in the cold insulating layer of the low temperature tank is adjusted to a constant pressure. |
