AIRTIGHT MECHANISM FOR CIRCULAR WATER STORAGE TANK, MANUFACTURING METHOD FOR HOLLOW-TUBE CIRCULAR BODY MADE OF FLEXIBLE SHEET USING THE SAME MECHANISM, AND APPLICATION METHOD FOR WATER STORAGE TANK USING THE SAME MECHANISM

摘要

PROBLEM TO BE SOLVED: To provide an airtight mechanism for a circular water storage tank capable of easily and effectively protecting sealing of a water storage space when repairing or mending a roof section of the circular water storage tank, and a manufacturing method for a hollow-tube circular body made of a flexible sheet used for the same mechanism capable of expanding in a circular state by injecting a gas and making the inner wall of a main body firmly stick on the peripheral edge section of the circular airtight sheet and preventing mixture of foreign bodies such as dust or the like. SOLUTION: The airtight mechanism for a circular water storage tank is provided with the circular airtight sheet built on an upper section of the main body of the circular water storage tank, and a hollow-tube polygonal circular body made of a flexible sheet. In the manufacturing method for a hollow-tube circular body made of a flexible sheet used for the airtight mechanism of the circular water storage tank, notches formed by two approximately sine curves joining both edges are formed on 15-60 places in the longitudinal direction of the flexible strip sheet, and a hollow-tube is formed by joining both edges of the flexible strip sheet after joining the flexible sheets adjacent to the notch. COPYRIGHT: (C)2008,JPO&INPIT