AGRU has been contracted to supply large diameter PE 100 pipes. The OD 1200 mm water main pipe was installed by horizontal directional drilling (HDD).
AGRU has been contracted to supply large diameter HDPE pipes in PE 100 for a unique project in Australia. The 282 m long OD 1200 mm SDR 11 (PN 16) water main pipe was installed by horizontal directional drilling (HDD) underneath the Wyong River as part of the Mardi to Mangrove Link project.
The project was constructed by John Holland Group for GWC Water, which is a joint venture between adjoining councils on the Central Coastof NSW (New South Wales, Australien).
The original design was a micro tunnel, utilizing MSCL (Mild Steel Concrete Lined) pipes. The project has been converted to directional drilling process using PE 100 pipes in order to eliminate the need for deep shafts, to reduce the risks associated with micro tunnelling in alluvial ground conditions as well as provide a reduction in project costs.
The specific complexness of the project
Production of the heavy wall PE 100 pipe in OD 1200 mm SDR 11: AGRU has achieved to supply extruded pipes with a wall thickness of 109 mm in a pipe length of 11,8 m (to reduce welds at site). In total 25 lengths were supplied and 24 pieces had been installed, as 1 pipe piece was kept as a spare for contingency purposes.
Pipes of this size were special ordered products from AGRU Austria and have never been handled before in Australia.
Welding of the pipes at site under stringent environment conditions: The welds were performed by the local company Kenkar using a hydraulically controlled trench butt welding equipment. The butt fusion process was executed acc. to validated DVS welding procedure and parameters. The qualified welders have performed 3 joints per day (in total 27 joints). The total preparation of the pipe string (282 m) before installation into the ground took 14 days.
Installation of PE 100, OD 1200 mm, PN 16 pipeline with HDD method was performed first time in Australia. The extremely limited access to exit and enter the site with products and equipment required innovative planning and solutions.
Limited number of calendar days to complete the project which was only achieved by applying PE 100 pipes and the HDD installation method: The pipe was hydrostatically pressure tested to 16 bar prior to insertion into the HDD bore. Installation of the pipe into the bore was completed within 12 hours.The pipeline links now two existing water storage facilities, Mardi Dam and Mangrove Creek Dam.
The pipeline links now two existing water storage facilities, Mardi Dam and Mangrove Creek Dam.