The new BBA PT Pumps are “seriously awesome” says Glenn Powell, the civil and mining territory manager north for Prime Pumps.
These pumps are expected to “transform” the well pointing/dewatering market here, he says, and make it far more efficient to dewater holes going forward.
“There’s also huge fuel savings to be made on traditional centrifugal pumps, increased service intervals, and a seven day refuelling cycle when running 24/7 instead of the normal refuelling after just two days.
“They are also the quietest pumps on the market – 48dB(A) and nothing can match this.”
How it works
Traditional centrifugal pumps are designed to push water – not pull it, says Glenn. “They need a vacuum pump to enable the water to be drawn up the intake pipe and into the pump impeller. Effectively, you have two pumps running off the one engine.
“Once the impeller has a full pipe of water right from the intake water level to the pump head it then forces the water out the discharge and, in doing that, creates a vacuum in the intake pipe which keeps the flow going so it continues to shift water at great efficiency, sucking water in while pushing liquid out the discharge pipe.
“While this is great for lowering the water level down very quickly, once the water level has got to its lowest point it then becomes very inefficient as you can have a large intake of air into the system.
“You then have a four cylinder engine running the pump impeller which is pumping only 10-20 percent of its potential capacity and at the same time running a vacuum pump which is working very hard to extract the air out of the whole intake system.”
Running a 50hp (37kW) engine on a pump that is only running at 10-20 percent efficiency is “nuts”, says Glenn. “As our Dutch friends said to us – they would go broke using centrifugal pumps for well-pointing in Holland – everywhere they dig they need to well-point.”
“So they have designed a specialist piston pump that can be run with a 7.9hp (5.8kW) single cylinder engine – that is one huge reduction in energy needed to do the same job and a massive (84 percent) reduction in power and that transforms direct to your profit margins.”
Glenn says think of a syringe – when you put it into a glass full of water and pull the internal sleeve back it draws whatever liquid or air is in the base of the glass – it’s called positive displacement. With a perfect vacuum to close on nine meters deep, the latest model has a capacity to 103 cubic metres per hour of water or air. “This does mean that the initial draw down of the water right at the start of the job does take a little longer than a centrifugal pump but that is by far made up for in the savings over the duration of the project.”
It can run also dry for as long as you like – the pistons are sealed with some simple leather cups so when there is no water, the cups just shrink a little (and just shines up the liners). When the water comes back the cups increase in size and fully seal again.
Other features include 1500 warrantied service hour intervals; a 65 percent reduction in servicing costs; up to 14 percent reduction in exhaust emission due to lower fuel consumption; a 25 percent saving on engine oil; a fully galvanised frame; colourfast polypropylene doors (no rusting); and fully bunded enclosure (spill free). It is also very light and compact, says Glenn.
Connell Contractors has a worksite on Madills Farm in Mission Bay, Auckland – constructing the Kohimarama Flood Mitigation Project.
Connells director Wayne Collinson says he didn’t know a pump could be so quiet.
“We have a worksite in Mission Bay area and are working in close quarters to high quality residential houses and have had issues with noise. By installing the PT90 Economy pump these issues have gone away, so has weekend refueling and constant checking.
“To be honest I was a little apprehensive when first talking to Glenn about this different style of pump, but he had such full confidence in the product he sent it direct to the site for a free no obligation trial period of two weeks – what happened at the end of two weeks? No hesitation, we brought it.”