Moomba to Adelaide Pipeline (Overpipe)
Epic Energy owns and operates the Moomba to Adelaide high-pressure gas transmission pipeline. Originally built in 1969, the main 22-inch (559mm) diameter steel pipeline is 781 km in length, supplying gas to Adelaide and regional areas.
Overpipe™ protection plates were installed over two primary sections of the pipeline near Booborowie and Auburn, north of Adelaide. Epic Energy selected the Overpipe™ OV1 plate for use on the pipeline. At 1250mm wide (1800mm in length) the selected size allowed sufficient overhang of 350mm on either side of the pipeline, preventing side intrusion on the pipe from an excavator bucket. Consecutive plates overlapped and were fastened to the preceding plate with a simple flange & plug connector.
In total 2.2km of Overpipe™ plates were installed to provide mechanical protection over sections of the pipeline, where there were potential encroachment or cover issues (such as deep ripping from farm machinery). The Overpipe™ plates were buried 300mm below the surface but up to 500mm below in areas of cultivation.
Installation was undertaken by Byrne Civil, who were laying up to 200m a day with a three-man crew (including the excavator operator). With 30 plates on a double pallet, transport to the remote sites was simple and no lifting gear was required. The Overpipe™ plates adapted well to varying terrain, including bends, hills, and creek crossings.
About Overpipe™ Protection Plates
The Overpipe™ HDPE mechanical protection plate was developed with GDF Suez (now Engie) R&D to provide an innovative alternative to concrete slabs. They are exclusively distributed in Australasia by Tapex Industrial.
Overpipe™ plates have been tested rigorously to meet the requirements of mechanical protection under AS2885. Overpipe™ is 15 mm thick and up to 2000 mm long, coming in widths from 570mm up to 2000 mm. Overpipe™ is designed to protect large-diameter buried pipelines (high-pressure gas, hydrocarbons, potable water, etc), high-voltage cables, critical water pipelines, and communication cables.
Made from injection-molded virgin HDPE, Overpipe™ plates perform consistently without splitting or cracking under penetrative attack. Most importantly, backed by a 50-year warranty, Overpipe™ provides long-term mechanical protection for any vulnerable buried assets. Overpipe™ is the solution when the possibility of 3rd party interference is an unacceptable risk to public safety and/or interruption of service.
Overpipe™ Installation
Quick to install, no specialist lifting machinery is required – reducing installation costs. Overpipe™ plates can in fact be reused after a pipeline has been uncovered for maintenance. The perforated plastic plates do not interfere with cathodic protection testing. The Overpipe™ Protection Plate fits the requirements of numerous utilities globally including Gaz de France, Saudi Aramco, Petronas, Total, Air Liquide & Fluxys, regarding the transportation by pipeline of high-pressure gas.
In Australia & New Zealand, Overpipe™ plates have now been approved for use above hydrocarbon pipelines by APA, Jemena, QGC, Shell, Sea Gas, Epic Energy, Tas Gas, Santos, First Gas & Vector.
Features
- Made from an injection moulded virgin HDPE polymer for consistency & strength.
- Holes across the surface of the plate allow the flow of water and no disruption of cathodic protection measurement. The holes are made by moulding and not by later drilling which would weaken the plates.
- The moulded non-slip surface on both sides helps to handle and avoids slip and fall accidents.
- Coloured and UV resistant to be an effective warning signal. Overpipe™ can be produced in different colours depending on the nature of the utility.
- Customizable warning message, moulded in relief into the surface.
- Lightweight (15 to 40 kilograms depending on the model), Overpipe™ is easy to install and remove to allow inspection or repair of the pipeline.
- The plates can be butted end to end or for total protection, overlapped using a unique clip system.
