| 摘要 |
PROBLEM TO BE SOLVED: To provide a hot water storage tank having excellent strength relative to negative pressure without adding a reinforcement ring.SOLUTION: A hot water storage tank 1 includes: a cylindrical tank body portion 2; a tank upper end plate 3 for closing an opening at one end of the tank body portion 2; and a tank lower end plate 4 for closing an opening at the other end of the tank body portion 2. On the surface of the tank body portion 2, a plurality of recessed portions 5 are provided in a range separated from one end and the other end by a predetermined distance or longer in the cylindrical axial direction and the circumferential direction of the tank body portion 2. The bottom surface of the recessed portion 5 has a regular polygonal shape, and the width of a clearance between the recessed portions 5 formed on the back surface side of the tank body portion 2 is equal to or shorter than the length of one side of the bottom surface of the recessed portion 5.SELECTED DRAWING: Figure 1 |
