Flexibore 400 withstands more pressure than fibreglass pipe

A large iron ore miner uses Crusader Hose layflat hose for mine dewatering.

Crusader Hose has helped keep Australia’s largest iron ore mines operating by releasing a layflat hose that boasts the highest pressure capacity in the world.

Crusader Hose has strengthened its 35-year history in ground water pumping solutions with the development of Flexibore 400. 

The ultra-high-pressure hose series was a result of Crusader Hose’s research and development in the area of bore water extraction, cementing the Melbourne-based company’s status as an innovative Australian manufacturer of layflat hose, flexible rising main and mine dewatering hose. 

The breakthrough comes in the form of a six-inch Flexibore 400 series hose, which is the highest pressure layflat hose in the world for mine dewatering, boasting a burst pressure of 90 bar or 900 metres.

The iron ore mines in the Pilbara region of Western Australia are a leading powerhouse for the Australian economy. These mines are at the cutting edge of best practice in efficiency and safety. 

Australian mining engineering is highly rated across the world due to its skilled processing and ore extraction techniques. 

“In some of the larger open cut iron ore mines, they have been working for over 30 years, non-stop, removing ore out of the pit. Some of the larger mines are longer than 25 kilometres, so you can imagine the experience gained plus size of hole in the ground,” Crusader Hose managing director Francois Steverlynck says.

To extract the ore in a dry state, the open cut mine needs to keep the water table lowered. This is typically achieved by pumping groundwater out from in-pit bores. 

These are the bores that are inside the open cut mine, as opposed to around the perimeter. 

Due to the constantly changing topography inside the pit, as the mine extends and deepens, these in-pit bores need to be moved and relocated. 

Flexible rising mains have been the system of choice for in-pit bores due to the simplicity with which the submersible pumps can be retrieved and installed. 

The typical installation method uses a roller, crane or mechanised spool, as the riser pipe is one continuous length.

The Flexibore 400 series hose has a burst pressure of 90 bar.

 

As the need to extract ore from deeper depths inside the pit has evolved, so has the importance of lowering the water table below the pit base. 

When the water table goes deeper down, the end result is a need for higher pressure pumps and higher-pressure riser pipes.  

Until recently, only fibreglass riser pipe had the pressure rating for this application, as Australian-made Flexibore and Well hose, an imported United Kingdom hose, both reached their safe operational pressure limits. 

Fibreglass, however, is not the ideal solution as it’s bulky, expensive and cumbersome to install. 

Therefore, discussions were initiated with dewatering supervisors of the large Western Australian mines for the need of a higher pressure Flexibore hose. 

The engineers at Crusader Hose rose to the challenge of developing a world-first product, and in June last year successfully trialled a six-inch Flexibore 400 which bursts at 90 bar. 

Groundwater can now be safely pumped from 360 metres below, or at higher pressures. 

The tensile load reached was 25 tons (22.6 tonnes), which represents the pump plus water weight that can be safely suspended from the Flexibore hose. 

“This is a pioneering achievement in the history of our company,” Steverlynck says. “This Australian development will hopefully be keenly adopted by the mining companies and enable them to keep at the forefront of productivity and continuous improvement.”  

This story also appears in the May issue of Australian Mining.

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