Pro Pipe Services was recently engaged by one of Australia’s major pipeline operators to remove two 34-inch (DN850) Class 600 LOCK-O-RING® Plugs installed over 46 years ago on the Moomba to Wilton Pipeline.
The job had many challenges associated with it, including the remote location, the extreme weather, and the fact the plugs were installed over 46 years ago.
Director of Pro Pipe Services, Joe Buttigieg, said Pro Pipe Services are proud to be an Australian owned company, utilising Australian technicians and resources to provide services to Australia’s pipeline industry.
“We are also proud to be associated with the largest High Pressure Line Isolation performed in Australia,” he said.
Pro Pipe Services were initially engaged to install two 34-inch (DN850) full bore ball valves, weighing approximately 14 tonne each, and to retract and remove the LOCK-O-RING plugs through the valves to provide gas for a new compressor station.
Using a TDW 936 Tapping machine, the first retrieval went like clockwork, and was completed in a matter of days. The second, however, proved to be much more of a challenge.
Some of the segments which hold the plug-in place on the second LOCK-O-RING flange would not retract. Following several attempts, the team decided that a line isolation was necessary in order to depressurise a section of the pipe which would allow for the removal of the plug and installation of the new 34-inch ball valve.
A TDW 34 Inch Class 600 STOPPLE® Fitting was welded onto the pipeline and Pro Pipe Services was engaged to complete the 34-inch high pressure hot tap and line isolation.
The Pro Pipe Services team achieved an excellent isolation, with no leak coming from the sealing element. This success allowed Pro Pipe Services’ technicians to use the TDW 936 Tapping to remove the LOCK-O-RING plug.
During the removal process, it was determined that some of the segments holding the plug in place had been damaged across its 46 year lifespan. This made it difficult to remove the plug the conventional way – to overcome this, the Pro Pipe Services team developed a method a method to safely retract the damaged segments.
Once the plug was removed, a 34-inch gas bag was installed into the fitting, allowing technicians to overhaul and rebuild the LOCK-O-RING flange. The flange was then pressure tested and the 34-inch valve installed, the bag removed and the valve closed. The Pro Pipe Services technicians then retracted the STOPPLE plugging machine and installed the completion plug.
To see more images taken of the project by the Pro Pipe Services team, click here.
For more information, visit Pro Pipe Services.
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