Large Diameter In-Tank Repair on Ropes

Overview

An in-situ repair was required to reinstate the integrity of a leaking sea-water ballast tank caisson. The application environment was hot with high relative humidity.

The repair site was 6 meters above base level of the tank, requiring the work to be carried out on ropes.

Scope

The line had the following specifications:

Structure	Ballast Tank Caisson
Surface Preparation	Sa 2.5
Class Approval	ABS & Lloyds
Design Pressure	300 kPa
Design Temperature	900C
Application Temperature	300C
Design Life	10 years
Wrap Length	1.2 m
Pipe Diameter	1.1 m
Geometry	Pipe, metal clamp, bolts, and seal nut
Corrosion Type	Internal
Defect Details	100 mm circumferential slot

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Solution

• Confined space and rope access trained personnel were required
• Temporary clamp used to seal live leak
• Technowrap 2K™ HA system used to wrap the large diameter pipe and temporary steel clamps, which created complex geometries
• Fatigue management system employed due to the hot and humid environment inside the ballast tank
• Detailed QA/QC procedures captured repair details for future reference

Benefits

• No hot works required
• The Applicator's extensive experience ensured the wrap was applied to a high quality despite quick curing times due to the application temperature
• A commitment to the Client's safety processes and ongoing communication ensured the job was completed safely with high productivity
• Careful monitoring and documenting of QA procedures ensured a high quality wrap despite the high ambient temperature and relative humidity