Learnings

Outcomes

With the success of the installation of the permanent clamp, WWU is able to reduce significant costs and maintenance by installing a permanent clamp immediately in case of emergency or by replacing a temporary clamp with a permanent clamp once. The clamp can be installed on a live pipeline. Moreover, the integrity is increased due to fact that the clamp and sealing can be tested in field on performance. 

The next step is to procure the clamp for all diameters.       

Delay in planning was also caused due to COVID-19 and delay at the manufacturer of the clamp.

The project has moved from 3 to TRL 8

Lessons Learnt

The permanent clamp was successfully installed on the pipe after the successful removal of the temporary repair clamp. The permanent clamp can be deployed on a large scale as a standard repair method taken into account the following amendments:

• Design (dimensions/weight) of the permanent clamp should be added for all possible pipe diameters. The trial assessed and designed for 6 inch pipe diameter.
• Correct handling and storage of the clamps prior to installation is critical particularly with regards the clamp seals.
• Depending on the size and weight of the clamp an appropriate lifting procedure may be required for all lifting operations (removal and installation of clamps).
• Lubricant 1000 Molykote or an equivalent product can be used.
• The surface preparation requirement can be modified to ST2 and ST3. 

It is advised to monitor performance after the installation on a regular basis to have a complete file and overview. 

Changes made to the T/PM/P/18 ‘Management Procedure for Working on Pipelines Equal to or Greater then 100mm Nominal Diameter Containing Defective Girth Welds or Girth Welds of Unknown Quality’ came into effect during the course of this project. These changes resulted in the girth welds adjacent to the temporary repair clamp having to be assessed via PAUT inspection. The result of the inspection was the requirement for the fitting of epoxy shells prior to works being undertaken to remove the PLIDCO temporary repair clamp, and fit the permanent solution. Although this was unforeseen, such assessments, and 

The cost & time associated with the PAUT inspection, and the fitting of epoxy shells should be built into future projects.