Industrial pumps are greatly affected by worldwide events as well as new technology. Products become available as the market demands them and the technology is there to produce them. Ann James of the market research company McIlvaine gives an overview of the changes of the last few years that have influenced key factors in pump development.

In the last few years the emphasis in pumps has been on life cycle costs, pollution including Green House Gas (GHG), variable speed drives and computer controlled programs, high pressure pumps, evolving materials of construction, and continued consolidation in the pump manufacturing companies. Life cycle costs should be considered before carrying out a major overhaul or building a new plant. In many cases, it costs more to operate a pump for one year than it does to buy the original pump. A reduction in operating costs of 20% can pay the pump’s cost in a little over a year’s time. In hard-to-pump fluids, the purchase price can be insignificant in comparison with the operating costs over the life of the pump.

Stricter rules

Industrial plants now face stricter rules regarding air pollution, especially GHGs from pump emissions mostly from seals. Some plants have bought sealless, either canned or magnetic, pumps. Canned motor pumps with casings designed according to API specifications provide reliable methods of preventing azardous media escaping to the environment. Hermetically sealed liners generally of Hastelloy construction) isolate the rotor core and stator windings from the process fluid. To compete with sealless pumps, seal manufacturers have developed new seals that prevent emissions. With conventional, liquid-lubricated seals, poor assembly and installation are common causes of seal wear and failure. Gas-lubricated non-contacting seals prevent emissions and protect product purity.

In the last few years, variable frequency drives have become increasing popular for the control of pump flow rates. These drives have a significant advantage over throttle valves in controlling rates of flow. Energy savings are large as is the cost savings if the drives are used correctly. Variable speed pumping changes the speeds of the pump instead of changing the system resistance to reduce the flow produced by the pump. Life cycle cost of variable-speed pumping thus becomes competitive. Recent studies suggest that some variable speed systems can pay for themselves in one or two years.

Sophisticated control

Computer software-controlled plants are becoming more sophisticated and cost effective. These programs also lead to automatic alerts for operators of impending problems, built in technology to monitor and interpret readings and plan maintenance/repair, built-in fail safe capabilities, and less time and personnel for walk arounds to view equipment. Although the oil supply is peaking, there is no decrease in the demand for pumps associated with extraction. More wells are being drilled, but the output of the new sources is low compared to the output of older wells, which are being depleted. High-pressure water injection pumps are now being used to increase flow from old wells.

Special high pressure pumps are also needed in desalination. The world’s supply of uncontaminated fresh water is shrinking while the residential, commercial, and industrial demand for fresh water is increasing. A high-pressure pump generates the pressure needed to enable the water to pass through the RO system membrane. Favourable experience with variable speed drives in power conservation for high-pressure pumps has led to the development of micro drives.

New applications

Raw material manufacturers have not been standing still. New material applications are being used for both pumps and seals. Not so many years ago, engineers used plastic pumps up to the maximum temperature established for PVC (140ºF/60ºC). With the availability of the fluoropolymers such as Kynar® and Teflon®, that upper temperature limit has more than doubled. This has expanded options to include thermoplastic pumps and other fluid handling equipment for a wide range of applications involving temperatures from –40ºF to well above boiling.

A similar misunderstanding about non-metallics has stood in the way of their being specified for handling abrasive corrosive fluids. Traditional thought was that such service requires stainless steel pump construction. The facts clearly indicate that thermoplastic materials are far superior to the stainless steels when tested for wear resistance. Additionally, pump manufacturers are developing other metals and metal combinations as well as using nanotechnology to make pump liners for corrosive media.

Pump seals

New materials are also being used for pump seals. Face seals with alpha sintered silicon carbide stationary faces and tungsten carbide rotating faces with nickel binders have been very successful in withstanding deterioration.
The industry continues to consolidate worldwide. The big companies are continuing to acquire smaller ones and make the market truly global. IDEX Corporation has announced the acquisition of Richter Chemie-Technik, a leading provider of premium quality lined pumps, valves and control equipment for the chemical, fine chemical and pharmaceutical industries. Textron Inc. announced that it has reached a definitive agreement to sell its fluid & power business unit, which is Gear Technologies, Hydraulics, Maag Pump Systems, Union Pump and each of their respective brands, to Clyde Blowers Limited.

Leave a Reply