CWC Removal
Concrete Weight Coat (CWC) Removal from a Steel Pipeline
This is an established and well-proven technique for removing short sections of Concrete Weight Coat (CWC) from a steel pipeline for:
1. Pipe repairs, investigation or tie in of another pipe. This may be onshore or in a habitat.
2. Pipe “cut to length” whether on a pipelay vessel or onshore.
We team up with another specialist who cuts the slots in the CWC and ThinJack Ltd removes the Concrete Weight Coat, as shown in photographs A to E below.
For subsea pipelines, one of ThinJack Ltd's (non-diving) technicians works with those who are inside the subsea habitat. They install and operate the ThinJack system, and our technician supports you with knowledge and guidance.
Summary
A
Tracks are cut in the concrete jacket: one track axially, along the crown of the pipe at 12 o’clock, and up to two tracks radially.
B
One of several curved ThinJacks inserted into a radial track before inflation.
C
The same ThinJack inflated with 400 bar of pressure, with a stroke of around 10 to 12 mm, forcing the CWC in an along pipe direction with a force of around 200 tonnes.
D
To finish: An axial or straight ThinJack inflates, pushing the 12 o’clock crown of the pipe in a radial direction.
E
Leaving the CWC exfoliated, or peeled off, below. The adhesive mastic covers the steel pipe.