An Australian company that specializes in both on-site and off-site pump refurbishment is finding that energy efficiency is an important driver in its refurbishment packages—and has included Vesconite bushings as part of its energy-reducing refurbishment package. FITT Resources’ Daniel Hechter says that electricity costs in Australia, at 25+ AUS c/kWh, are among the highest costs globally. As a result, when the company retrofits thirty to thirty-five-year-old pumps, besides increasing the life of a pump, there is a focus on increasing the energy efficiency of the pump.
PROGRAM ORIENTATED RETROFITTING
The company’s retrofitting is program orientated and includes a number of interventions to increase energy efficiency by ensuring that flow is better and that less electricity is used. One of the retrofitting tasks is to typically install Vesconite bushings as interstage bushings in the multi-stage high and low-pressure pumps that it repairs.
Vesconite is a very strong, wear-resistant, low-friction engineered plastic that is also dimensionally stable in water. Importantly, bushings produced from this polymer are ideal for dry startup, since they can run up to one minute dry.
The pumps that FITT Resources repairs have used bronze bushings historically and this has been expensive and caused damage to shafts. The Vesconite bushings, in contrast, offer the advantage of being able to run with small clearances, which causes less recycle, or less movement of pressurized water from the previous stage to the next stage.
REDUCING ENERGY CONSUMPTION
Hechter notes that it is difficult to determine the exact energy savings that can be attributed to the bushings, but energy consumption is reduced in general following a refurbishment package.
“Capital and labor are expensive in Australia, so it is important to use retrofitting to return original equipment manufacturer (OEM) equipment to its original if not better state,” he notes.
Water utilities in the region continue to rely on the pump refurbishment firm, which is also a supplier of OEM pumps, seals, and filtration systems, to refit their multi-stage pumps, and in the last four years, several multi-stage pumps have been retrofitted with either Vesconite Hilube or Vesconite bushings.
A two-stage horizontal split-case pump, with Vesconite inter stage center bushing
MORE EFFICIENT PUMPING
Many pump users are intent on reducing their energy demands. The electricity used in pumping is considerable so the benefits of reducing electricity consumption and costs through right-sizing and minimizing vibration, heat, and noise are key. One of the advantages of Vesconite Bearings’ bushings is that they have a low coefficient of friction and make pumping more efficient. This translates into a reduction in energy consumption.
The U.S. Department of Energy has been developing the Energy Conservation Standard for Pumps, which will require the manufacturers of end suction close-coupled, end suction frame-mounted, in-line, radially split multi-stage vertical in-line diffuser casing, and vertical turbine submersible pumps to meet certain minimum efficiency levels.
ONLINE CALCULATION TOOLS FOR VESCONITE BUSHINGS
Those who routinely calculate bushing sizes might be interested in Vesconite bushing calculators—which are among the more popular pages on the company’s website, www.vesconite.com. There are separate calculation tools for Vesconite bushings intended for general industry and for the pumps industry. There are also tools for rudder bearing and stern tube calculations for the marine industry.
Each of these calculation tools contains specific information that might affect final designs for the outside and inside diameters of bushings as well as their lengths. Minimum and maximum temperatures, total mass supported, number of bushings supporting the total mass, rotation, oscillation, linear movement, and linear cycles per minute are some of the criteria that may influence bushing design, as will a requirement for a press fit of the bushing, the calculator table indicates.
Vesconite Bearings encourages clients to try out the calculators, which are made for metric and imperial measurements. The calculators provide helpful hints on where a user’s inputs need to be altered, a not-to-scale diagram of the required bushing, and an invitation to print your results or to share your results with Vesconite Bearings for checking and for quotation.
A HISTORY OF PERFORMANCE
The Vesconite story goes right back to 1968 when chemical engineer Alain Francois Leger began researching the potential for polymer bushing materials in the gold mines of South Africa’s Orange Free State–harsh environment characterized by dirty and wet conditions.
Fifty years on, the producer of Vesconite is South Africa’s leading manufacturer of low friction, low wear polymer bushing materials for a wide range of industries in over 100 countries across the globe. These include agriculture, railways, mining, pumps, heavy transport, hydro, wind turbine, earthmoving, and marine industries.
For more information:
The Vesconite factory features advanced extrusion, injection molding, and machining facilities. The factory produces both standard stock (rods, bushings and plates) and high quality finished parts. The producer of Vesconite also has warehouses in South Africa, the United States, United Kingdom, Netherlands, and New Zealand, with stocking distributors in Argentina, Australia, and Singapore. For more information, visit www.vesconite.com.
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MODERN PUMPING TODAY, October 2017
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