Pump has key role in high-pressure pipeline test units

Six high-pressure testing and water-blasting units have been manufactured to contribute a key role to the Wimmera Mallee Pipeline Project - one of Australia's largest regional infrastructure projects.

The first stage of the $522 million project, being managed by GWM Water as a partnership by the Australian and Victorian governments, for which the successful tenderer has just been announced, will save an estimated 13,000 ML of water with customers expected to be able to draw on the piped supply under a fast track construction schedule by October this year.

The contract for the first stage of construction has been awarded to civil engineers and pipeline contractors Mitchell Water.

Mitchell Water has its operations base in Seymour Victoria with operations also in Western Australia and South Australia, while Horsham will be its principal operating base for its new project.

The first stage works include a gravity feed trunk pipeline from Lake Bellfield in the Grampians to Taylors Lake near Horsham and will be a cement-lined mild steel pipeline.

The second stage from Taylors Lake through the towns of Dooen, Dimboola, Rainbow and Yaapeet serving local communities and farms will be a PVC pipeline, with a series of pump stations and booster pumps.

Recognising that they would require high-pressure testing units to test the pipelines before they are commissioned and that high-pressure water blasting would be a preferred access rather than manual or mechanical excavation at a number of sites where there are existing in-ground services like gas mains or other infrastructure, Mitchell Water consulted with local company Seymour Pump Shop headed by Jack Tennant.

Seymour Pump Shop has now designed and built six trailer-mounted high-pressure testing units which are able to perform both tasks.

Two engine-powered pump sets are mounted on the trailer chassis along with an 800 L capacity storage tank.

The high-pressure pump set designed to achieve a high-pressure, high-volume water source saw a number of commercially available engine-powered pump sets tested until a Davey Firefighter Twin with twin impellers and a 13 hp Briggs & Stratton Vanguard engine demonstrated its capacity to achieve the desired performance.

The second pump set powers a 2 m long stainless steel lance with a special nozzle fitted which acts as a handpiece and is able to blow a hole of large enough diameter to enable the pipe system to be inserted into the space created.

Seymour Pump Shop's principal Jack Tennat says he spent almost six months designing and testing the units to achieve the right performance specifications. "We have source off-the-shelf pump units and plumbing components as far as practical. "Designing the blasting lance was a real challenge as we needed to both blast the hole and remove the spoil. "And as far as possible we wanted to be able to recycle as much of the 800 L water storage capacity of the tank as practical.

Six of the testing units have now been delivered.