Pipeline Ultraisolation Group (PLUG)
Reliable services for inline isolation tools
Who We Are
PLUG, Pipeline Ultraisolation Group, is developing the latest in a series of tools that are designed to seal off flow in an active pipeline where a valve may not be present. PLUG offers an alternative to purging the entire line with nitrogen, or hot tapping into a live pipeline to install a temporary plug. Unlike hot tapping, the use of an inline plugging pig leaves no fittings on the line, thus eliminating a potential site for future corrosion. The plug’s applications include repair work, reroutes, mainline valve changeouts, launcher and receiver valve changeouts, removal of old line stop fittings, and any other applications where and line stopping technologies have been used in the past.
How it works
The plugging tool consists of several modules; the plug modules, a control module, and a pigging module. During a job, the tool is run down the line with normal product flow, to a predetermined location. Then flow is stopped, the tool is located, and two-way, through wall communications are established with the control module on the tool. When the command is given, the control module injects fluid into a piston inside the working head of the tool. This piston draws the two ends of the working head together. This causes specialized grips to move up a ramp and expand outwards against the wall of the pipe, to anchor the tool in place. Further compression of the tool squeezes a rubber element, the packer, outwards against the wall of the pipe, creating a vapor tight seal. Any differential pressure across the tool compresses the tool further, increasing both the effective seal, and the force with which the grips anchor the tool to the pipe wall, making it impossible for a pressure spike to cause the tool to move, when in service.