Pratt, who has been in a number of senior management positions with leading water and wastewater pumping companies supplying to the mining industry over the past 30-plus years, heads the expanding pumping division at Western Australia-headquartered Murray Engineering. He's sold some of the world's top pump brands over his long career but wasn't quite prepared for the results of early installations of the MEPS dewatering units at WA mines.

"The first MEPS units - both the helical rotor and the heavy duty centrifugal - were installed underground at different sites in late 2017,"Pratt says.

"The centrifugal MEPS at a leading Goldfields mine have been pumping a very aggressive and salty water. In fact some say the water can be as much as 25-27 times saltier than sea water. People on site are extremely impressed with the performance of these pumps. The extended life of these pumps is proving to be far superior than other brands of helical rotor pumps.

"To date not a spanner has been put to either of the MEPS installed at the mine and pumps and parts are still in stock on site as they have had no need to use them."

Murray Engineering worked with Byrnecut Group on the design of the underground pump stations. Byrnecut is one of the world's leading underground mining contract services companies with operations throughout Australia and offshore.

Pratt says the helical rotor and centrifugal pumps provided value and performance advantages over popular, traditionally used products.

But service and spare parts aftermarket activity might be thin on the ground if early indications are a reliable guide to the future.

"When we first installed both the new MEPS back in late 2017 we supplied back-up pumps and spares as the pumps were new to the underground mining market," Pratt says.

"They haven't put a spanner to either MEPS, which is quite remarkable in my experience.

"Both the helical rotor and the heavy-duty centrifugal pumps are very well designed and clearly are going to last a lot longer than the products that have typically been used at mines in the past.

"Both pumps bring some different features to the market.

"For example, the helical rotor pump runs slower than a [comparable] Mono pump to deliver the same flow. Generally speaking if you run a pump slower you're going to get an extended life.

"They have sealed-for-life bearings so you don't have to keep greasing the bearings all the time, which is another huge advantage.

"They also come fitted standard with a mechanical seal, so your fitters are not going underground every day checking to see if the gland packing has worn or leaking, and to check the bearings.

"So there is a huge maintenance saving on them."

The 55-90kW helical rotor MEPS supplied so far have been set up to achieve 20 litres-per-second duties on dirty mine water (up to 5% solids) with heads of 180-240m. Centrifugal units with 90-110kW motors are transferring 38-48 litres/second in harsher mine-water (including mild slurry) duties, with heads typically 140-160m.

Pratt says the helical rotors are available in wear and corrosion resistant materials to suit very abrasive and corrosive applications.

The MEPS with helical rotor pump has been designed and built to "drop into" different site footprints without any need for pipework modifications. Murray Engineering is typically supplying the units skid-mounted with hoppers, inspection ladders and platforms, pipework, flow meters and valves.

A number of MEPS stations have been supplied in Australia and internationally, and Murray Engineering has a solid order pipeline.

"The take-up so far has been very good," Pratt says.

"We think when the market gets wind of the performance and maintenance benefits of both the helical rotor and centrifugal pumps compared with some of the incumbents we're going to be even busier supplying these MEPS pump stations."