A 10-in., 1.86-mi inversion lining undersea and a follow-up study after 30+ years

摘要

This paper introduces a submarine pipe rehabilitation project that was installed more than 30 years ago and the recent study on assessing the integrity of the liner. The initial lining project was very challenging in that:1) A DN250 (10”) liner was inverted for approximately 3,000 m (1.86 miles) in one shot.2) The host pipe to be lined was mostly laid undersea.3) The pipeline was a pressure pipe for conveying petroleum products.The paper explains the initial project back in 1985, periodic inspections after project completion and the recent study on verifying the integrity of the liner. The explanation of the initial project covers conditions of construction, requirements for the lining method and the lining process. Because the liner used was a non-structural type, the recent study on liner’s integrity focused mainly on the condition of the inner-coating layer and the water tightness. The study involved observation by SEM and an airtightness test which proved that no crucial defects were found in the liner.By describing the initial rehabilitation project and the follow-up study after 30+ years, this paper documents a practical method for corrosion prevention using a non-structural liner.