Abstract
Although polyethylene pipes have come into use with the low pressure gas pipelines in recent years, previous to their introduction, galvanized steel pipes, asphalt jute covered steel pipelines, etc. were used, and because more than 30 years have passed since these were installed, they are now at risk of leakage caused by corrosion. To cope with this problem, gas companies have applied some rehabilitation methods that are countermeasures that can be executed at low cost, in order to encourage measures to protect aged pipelines from the risk of corrosion. The rehabilitation method is a technology executed by forming an epoxy resin membrane inside gas pipes to prevent gas leakage even after corrosion holes have appeared in the pipeline.
But among the methods initially applied, some were executed more than 20 years ago, and their durability is the object of concern. So at the same time as a method of evaluating the long term durability of epoxy resin, that we have used for these rehabilitation methods, has been established, the appropriateness of the method has been confirmed.
So this paper will announce these long term durability evaluation methods along with the results of the verification of the suitability of the method.
