Negative pressure generating prevention structure and negative pressure generating prevention method to be used when MizuCho pressure test of the reservoir

摘要

PROBLEM TO BE SOLVED: To provide a negative pressure generation preventing structure and a negative pressure generation preventing method which use an intake and exhaust device in a water-filled pressure test so that the intake and exhaust device sucks air automatically to prevent a negative pressure state inside a storage tank caused by mistakes such as forgetting and delay of valve operation of an opening part of a manhole and vent pipe on an upper part, valve failure, and shortage of an intake amount or the like in the water-filled pressure test.;SOLUTION: The integrated type intake and exhaust device 5 has an air vent function in filling water, a pressure-resistant sealing function which prevents leakage of water when water is fully filled, and an intake function in draining water, and is formed of a buoyancy valve element 6, a seal surface body 7, and a support frame body 8. The intake and exhaust device 5 is arranged on an upper opening part 3 of a storage tank top part.;COPYRIGHT: (C)2012,JPO&INPIT