DEVICE FOR MEASURING BELLOWS WALL THICKNESS OF EXPANSION

摘要

PROBLEM TO BE SOLVED: To measure the wall thickness ratio between a wall thickness of a ridge part of the bellows of an expansion and its initial wall thickness, even in course of plant operation.;SOLUTION: A relation curve between the wall thickness ratio t/t₀ of the ridge part of the bellows of an expansion and a spring constant ratio K/K₀ of the expansion, is stored beforehand in a memory device 14. A spring constant ratio calculation means 13 calculates the spring constant ratio K/K₀ between the spring constant K and the initial spring constant K₀, by using an axial or circumferential strain of the expansion detected by a strain sensor 11 arranged in a trough part of the bellows of the expansion, and an initial axial strain or initial circumferential strain. A wall thickness ratio calculation means 15 finds the wall thickness ratio t/t₀ of the ridge part of the bellows of the expansion, based on the spring constant ratio K/K₀ calculated by the calculation means 13 and the relation curve stored in the memory device 14, and outputs the ratio to an output device 16.;COPYRIGHT: (C)2010,JPO&INPIT