- Email: [email protected]
Does the world need more submersible pumps, or better pumps and installations?
feature submersible pumps
Does the world need more submersible pumps, or better pumps and installations? World Pumps discusses with Henrik Mogensen, the CEO of PXPumps, what the challenges are that now face the pump industry – and how the over-specification of submersible pump needs could lead to a serious waste of energy and costs.
W
ith the proliferation of pump manufacturers around the world and the increase in manufacturers from rapidly industrialising countries such as China and India, is there a market or a requirement for a wider choice? When PXPumps was launched early in 2005 with a range of submersible pumps for water and sewage applications, it may
have been asked in the industry if there was need for yet another manufacturer. However, is it simply a case of too many pump manufacturers or is the problem deeper than that? “It is true that there are a great many manufacturers of pumps from all parts of the world, many having been established for many years,” replies
Henrik Mogensen. “But there will always be room for products that bring innovations, more reliability and improved efficiency, especially when this is combined with a significant customer base that can no longer access the pumps it has come to trust because the company has ceased production, merged or stopped supporting various markets. “Successful distributors around the world were left in a very difficult position when Cardo decided to realign their pump manufacturing. The new range of PXPumps is designed to be compatible with the former Pumpex range, which merged into the ABS range of pumps 15 months ago. This left many well established distributors with a loyal customer base without products to sell.” The largest of these was the Pumpex A/S, which had been a Pumpex distributor for 30 years. “We had a major dilemma,” says Mogensen, “and we had to make a quick decision. We had a large customer base and a large population of pumps to service and maintain. We could not simply walk away from a business established over decades.”
PXPump UVAC installation.
24
0262 1762/06 © 2006 Elsevier Ltd. All rights reserved
The company’s directors made the decision to form a new company to design a completely new range of submersible pumps that offered a high degree of compatibility with existing pumps. This was to be achieved using interchangeable
WORLD PUMPS July 2006
feature submersible pumps components or as a simple direct replacement pump set. The newly formed company approached distributors around the world, of which over 40 companies reached a new agreement to distribute the pumps. However, having a range of pumps compatible with existing customer base requirements was not, in itself, enough to guarantee success. Pumps can be, in many installations, critical units that have to be able to cope with tough demands with a high degree of reliability and efficiency. Additionally, an effective parts and support service is an essential requirement. Such is the demand for reliability that often larger pumps will be specified under the assumption that larger pumps are more reliable. The company decided to take on this challenge, by asking customers to look anew at advances made by pumping technology over the years and to stop using out-dated thinking and policies – attitudes which, if changed, could reduce owning and operating costs significantly. “This is the biggest challenge”, says Mogensen, “because it is easier, perhaps safer, to use proven practices, instead of re-evaluating solutions. But rising energy costs will force consultants and customers to rethink strategies.”
Advanced product design The company felt that that to succeed they had to offer added value while attempting to remain costcompetitive. They also felt that they could not be too innovative with an unproven product. As a result, they have incorporated some proven features into the entire range of pumps, which, the company says, can improve performance, reliability and reduce service times by making maintenance procedures easier. All PXPumps feature two or four stainless steel latch bolts instead of the usually eight or more studs
WORLD PUMPS July 2006
which can sometimes get clogged up with material so need to be cleaned before they can be unscrewed – and there can be a risk of them falling into the bottom of the pump. With the latch bolts, the motor unit can be removed and, in dry pit installations, the volute remains in the pipe system. The latch bolts have been sized to prevent loosening by vibrations. Another aid to easier maintenance which the company maintains is available in this range is the use of double mechanical seals supplied in a user-friendly cartridge. With three cartridge sizes to cover the full range, inventory is kept low and the cartridges can be replaced on-site without any special tools. Other features such as oversized shafts can help to provide smooth, vibration free running even when they are at full power and EFF 1 electric motor units with Class H insulations and three thermal overload switches help provide a reliable drive system.
Improving operating efficiency Water cooling jackets are not new but this company is the first to build them in as standard to all pumps – for dry pit, portable and wet pit installations. Unlike some conventional jackets, which depend on the liquid being pumped for cooling, PXPumps jacket employ a closed loop system in which an internal impellor circulates a solution of 80% water and 20% glycol. Being a closed loop system, there is no risk of a blockage or silting, so cooling efficiency is much more possible. The PXPump solution also allows the pumps to run dry for extended periods and significantly reduces settlement of solids, the company maintains. “Cooling jackets have had a significant effect on pump design and they are standard today on many larger pumps,” says Mogensen.
The Electric Submersible pump.
PXPumps is, it says, the only company to offer them across the entire line. Because of improved pump cooling which cooling jackets provide, there is a rapidly growing trend towards dry pit installations. “The benefits of a dry pit installation, especially in sewage applications, are obvious to anyone who has had to work on a pump removed from a traditional installation, which will invariably be covered in sewage sludge,” says Mogensen. “Dry pit installations are also easier to service and require less downtime.” Mogensen says that sometimes, customers tend to be concerned about pumping efficiency without fully understanding how this is achieved.
www.worldpumps.com 25
feature submersible pumps “Manufacturers can easily increase hydraulic efficiency simply by reducing throughlet but this is not really optimising pumping efficiency,” he adds.
Proven inefficiencies in pump installations The inefficiency of the majority of pump installations has been demonstrated by the Finnish Technical Research Centre in a report, Expert Systems for Diagnosis and Performance of Centrifugal Pumps.
The PX3 duoble mechanical seal cartridge.
This report on a study of almost 2000 pumps in 20 plants showed that the average pumping efficiency was less than 40%. More alarming was the fact that 10% of these pumps operate at less than 10% efficiency. This is at a time when organisations are under extreme pressure to increase operating
Table 1. Operating cost comparison: two pump sizes for a 100-hp application a Performance
Pump oversized by 15% beyond flow requirement (150 hp)
Pump sized to meet flow requirement (100 hp)
Annual energy use
623,000 kWh
471,000 kWh
Annual energy cost
US$37,400
US$28,300
Lifetime energy cost b
US$392,000
US$296,000
–
US$96,000
Lifetime energy cost savings
a Assumes 6,000 operating hours, 95% motor efficiency, 75% pump efficiency, and $0.06/kWh. Lifetime energy cost is the sum of the discounted value of annual energy costs based on a pump life of 15 years. Future electricity price trends and a discount rate of 3.4% are based on federal guidelines (effective from April 2000 to March 2001). b Lifetime energy cost is the sum of the discounted value of the annual energy costs based on average usage and assumed equipment life of 15 years. Source: United States Department of Energy’s Federal Energy Management Program (FEMP).
Table 2: Operating cost comparison: two flow control options for a 100-hp application a Performance
Flow control by throttling
Flow control by speed adjustment
Annual energy use
380,000 kWh
282,000 kWh
Annual energy cost
US$22,800
US$16,900
Lifetime energy cost b
US$239,000
US$177,000
Lifetime energy cost savings
-
US$62,000
a Assumes 6,000 operating hours, 95% motor efficiency, 75% pump efficiency, and $0.06/kWh. Future electricity price trends and a discount rate of 3.4% are based on federal guidelines (effective from April 2000 to March 2001). b Lifetime energy cost is the sum of the discounted value of the annual energy costs based on average usage and assumed equipment life of 15 years. Source: United States Department of Energy’s Federal Energy Management Program (FEMP)
26
www.worldpumps.com
efficiency to reduce costs, and the growing awareness of environmental considerations of poor use of energy sources. One could assume that these installations were planned for operating efficiency. However, the evidence suggests that the evaluation model used in determining the most appropriate installation is seriously flawed. Among the many reasons for the extreme inefficiency of so many pump installations was the common trend to oversize pumps and to use throttling valves. However, it could be argued that excessive use of throttling valves is not an efficient solution. It has been reported that throttling a valve by 50% significantly increases damage to the valve installation. The resulting loss is not only in efficiency but also in higher, unnecessary installation, maintenance and operating costs. One reason for this is might be the fact that the pumps represent as little as 15% of a total installation and there is too little consideration given to ongoing operating costs. The philosophy can be that ‘pumps are cheap – so put in larger pumps’, resulting in oversizing pumps which, for the most part, operate well below their optimum efficiency point. This practice was acceptable when energy costs were low at a time when little consideration was given to environmental issues. In today’s cost, energy and environmental climate, it is arguably not acceptable, and plant operators are looking increasingly at ways to reduce costs. “Do not focus so much on pumping efficiency but on total operating costs,” is the advice from Mogensen. “Technology is making the efficiencies even more achievable. Variable speed drive pumps are one way to reduce costs but a downfall of normal impellers is the tendency to clogging at lower frequency. This, for the most part, can be overcome by using vortex impellers. It is true that vortex impellers are not as efficient, but they enable significant energy saving, reduce clogging and are a much lower cost unit. So over the life of the pump, the option is viable.”
WORLD PUMPS July 2006
feature submersible pumps Although the PXPump range is available with variable speed drives, the company reportedly does not want to over-emphasise the availability because, it says, the market does not fully appreciate the benefits and only sees the risks. “Unfortunately, pump manufacturers have to supply customer demand, even though so many of us can see that what the customer is demanding is not necessarily the most cost effective solution, but customers have to go by what is specified in the contract,” says Morgenson. Variable speed drives (VSD), used in conjunction with advanced, more sophisticated, sensors, superior valve design and computer technology have enabled pump manufactures to develop intelligent pumps.By definition, intelligent pumps optimise performance to meet demand at the lowest possible cost. Gould Pumps, in a case study entitled Intelligent Variable Speed Pumping Controls Costs states: “Centrifugal pumps consume, depending on the industry, between 25% and 60% of electrical motor energy . . . In poorly designed systems, maintenance can be more than 40%.” The case study further explains the possible savings in energy that can be made through greater use of intelligent pumping. For instance, replacing throttling valves with speed controls can deliver a saving of anything up to 60%. It is not only manufacturers that are promoting better pump installation specifications. As governments come under increasing pressure to reduce the demand for energy, they are also helping utility companies look at ways to operate more efficiently. In a study called How to Buy an Energy-Efficient Centrifugal Pumping System, the United States Department of Energy’s Federal Energy Management Program (FEMP) analyses the cost efficiencies that could be achievable by implementing a modern approach to specifications and the costs of oversizing pumps. Table 1, on the left-hand page, illustrates the saving possible in energy costs alone.
WORLD PUMPS July 2006
The same study says that proper pump selection should consider both constant and variable flow and head conditions. In systems with little change in demand, pumping system efficiency depends largely on selecting the correct pump size, while in systems with variable demand, pump system efficiency depends on effectively matching supply with demand, which can be achieved in several ways, depending on system requirements. Many installations have to be designed to cope with variations in demands. These systems invariably have oversized pumps and throttling valves. Table 2 shows the cost saving possible by switching to variable speed drive systems. These are pure energy savings and do not take into account other operating costs which will provide further savings.
Specifiers are overly conservative Talking to pump manufacturers shows that many of them believe that consultants and other specifiers of pump installations too often use evaluation models that have not been updated for many years and which fail to take account of advances over the years and rising energy costs. “By over specifying the pumps required they minimise the risk of insufficient pumping capacity but introduce serious operating inefficiencies and excessive operating and maintenance costs,” says Mogensen. “With the modern range of pumps available today, there are ways to build in additional capacity, which enable the primary pumps to work at optimum efficiency. Not only is this a lower cost option, it is a greener solution as it minimises energy requirements.” To encourage specifiers and customers to modernise their conservatism, the company has introduced a modern range of pumps, which can be packaged in a variety of configurations. This enables a certain degree of customisation to meet specific
installation needs, whether the pumps are a replacement of existing units or for a new installation.
Getting the priorities right At the beginning of this article, we asked “Does the world need more submersible pumps – or better pumps and installations?” and the answer is probably far from straightforward because pumping efficiency is not taken seriously enough in many applications. Although pumps represent a very small part of the total cost of a new installation, manufacturers are nevertheless under increasing pressure to reduce costs. Unit cost could be said to be the driving force and encouraging companies to enter the pump market with inferior, albeit cheap pumps. “Most manufacturers are only too pleased to meet with specifiers and customers in determining the most efficient solution. Manu-facturers are often forced to provide the lowest cost solution based on pump cost,” says Mogensen. “If the specifiers and customers will allow us to show them how to size a pump for the best efficiency point (BEP) the operating costs are optimised. However, this can be complex and is often the reason for oversizing the pump. I am not confident that we can change attitudes quickly, which is why mine and other companies have to offer variations, which, ironically, increase production costs.” This attitude of specifiers and customers is also observed by the United States Department of Energy’s Federal Energy Management Program which states that the conservative practices often prioritize initial performance over system life cycle costs. As a result, larger-thannecessary pumps are specified, resulting in systems that do not operate optimally. Increased awareness of the costs of specifying oversized pumps could potentially discourage this tendency. ■
www.worldpumps.com 27
Does the world need more submersible pumps, or better pumps and installations? World Pumps discusses with Henrik Mogensen, the CEO of PXPumps, what the challenges are that now face the pump industry – and how the over-specification of submersible pump needs could lead to a serious waste of energy and costs.
W
ith the proliferation of pump manufacturers around the world and the increase in manufacturers from rapidly industrialising countries such as China and India, is there a market or a requirement for a wider choice? When PXPumps was launched early in 2005 with a range of submersible pumps for water and sewage applications, it may
have been asked in the industry if there was need for yet another manufacturer. However, is it simply a case of too many pump manufacturers or is the problem deeper than that? “It is true that there are a great many manufacturers of pumps from all parts of the world, many having been established for many years,” replies
Henrik Mogensen. “But there will always be room for products that bring innovations, more reliability and improved efficiency, especially when this is combined with a significant customer base that can no longer access the pumps it has come to trust because the company has ceased production, merged or stopped supporting various markets. “Successful distributors around the world were left in a very difficult position when Cardo decided to realign their pump manufacturing. The new range of PXPumps is designed to be compatible with the former Pumpex range, which merged into the ABS range of pumps 15 months ago. This left many well established distributors with a loyal customer base without products to sell.” The largest of these was the Pumpex A/S, which had been a Pumpex distributor for 30 years. “We had a major dilemma,” says Mogensen, “and we had to make a quick decision. We had a large customer base and a large population of pumps to service and maintain. We could not simply walk away from a business established over decades.”
PXPump UVAC installation.
24
0262 1762/06 © 2006 Elsevier Ltd. All rights reserved
The company’s directors made the decision to form a new company to design a completely new range of submersible pumps that offered a high degree of compatibility with existing pumps. This was to be achieved using interchangeable
WORLD PUMPS July 2006
feature submersible pumps components or as a simple direct replacement pump set. The newly formed company approached distributors around the world, of which over 40 companies reached a new agreement to distribute the pumps. However, having a range of pumps compatible with existing customer base requirements was not, in itself, enough to guarantee success. Pumps can be, in many installations, critical units that have to be able to cope with tough demands with a high degree of reliability and efficiency. Additionally, an effective parts and support service is an essential requirement. Such is the demand for reliability that often larger pumps will be specified under the assumption that larger pumps are more reliable. The company decided to take on this challenge, by asking customers to look anew at advances made by pumping technology over the years and to stop using out-dated thinking and policies – attitudes which, if changed, could reduce owning and operating costs significantly. “This is the biggest challenge”, says Mogensen, “because it is easier, perhaps safer, to use proven practices, instead of re-evaluating solutions. But rising energy costs will force consultants and customers to rethink strategies.”
Advanced product design The company felt that that to succeed they had to offer added value while attempting to remain costcompetitive. They also felt that they could not be too innovative with an unproven product. As a result, they have incorporated some proven features into the entire range of pumps, which, the company says, can improve performance, reliability and reduce service times by making maintenance procedures easier. All PXPumps feature two or four stainless steel latch bolts instead of the usually eight or more studs
WORLD PUMPS July 2006
which can sometimes get clogged up with material so need to be cleaned before they can be unscrewed – and there can be a risk of them falling into the bottom of the pump. With the latch bolts, the motor unit can be removed and, in dry pit installations, the volute remains in the pipe system. The latch bolts have been sized to prevent loosening by vibrations. Another aid to easier maintenance which the company maintains is available in this range is the use of double mechanical seals supplied in a user-friendly cartridge. With three cartridge sizes to cover the full range, inventory is kept low and the cartridges can be replaced on-site without any special tools. Other features such as oversized shafts can help to provide smooth, vibration free running even when they are at full power and EFF 1 electric motor units with Class H insulations and three thermal overload switches help provide a reliable drive system.
Improving operating efficiency Water cooling jackets are not new but this company is the first to build them in as standard to all pumps – for dry pit, portable and wet pit installations. Unlike some conventional jackets, which depend on the liquid being pumped for cooling, PXPumps jacket employ a closed loop system in which an internal impellor circulates a solution of 80% water and 20% glycol. Being a closed loop system, there is no risk of a blockage or silting, so cooling efficiency is much more possible. The PXPump solution also allows the pumps to run dry for extended periods and significantly reduces settlement of solids, the company maintains. “Cooling jackets have had a significant effect on pump design and they are standard today on many larger pumps,” says Mogensen.
The Electric Submersible pump.
PXPumps is, it says, the only company to offer them across the entire line. Because of improved pump cooling which cooling jackets provide, there is a rapidly growing trend towards dry pit installations. “The benefits of a dry pit installation, especially in sewage applications, are obvious to anyone who has had to work on a pump removed from a traditional installation, which will invariably be covered in sewage sludge,” says Mogensen. “Dry pit installations are also easier to service and require less downtime.” Mogensen says that sometimes, customers tend to be concerned about pumping efficiency without fully understanding how this is achieved.
www.worldpumps.com 25
feature submersible pumps “Manufacturers can easily increase hydraulic efficiency simply by reducing throughlet but this is not really optimising pumping efficiency,” he adds.
Proven inefficiencies in pump installations The inefficiency of the majority of pump installations has been demonstrated by the Finnish Technical Research Centre in a report, Expert Systems for Diagnosis and Performance of Centrifugal Pumps.
The PX3 duoble mechanical seal cartridge.
This report on a study of almost 2000 pumps in 20 plants showed that the average pumping efficiency was less than 40%. More alarming was the fact that 10% of these pumps operate at less than 10% efficiency. This is at a time when organisations are under extreme pressure to increase operating
Table 1. Operating cost comparison: two pump sizes for a 100-hp application a Performance
Pump oversized by 15% beyond flow requirement (150 hp)
Pump sized to meet flow requirement (100 hp)
Annual energy use
623,000 kWh
471,000 kWh
Annual energy cost
US$37,400
US$28,300
Lifetime energy cost b
US$392,000
US$296,000
–
US$96,000
Lifetime energy cost savings
a Assumes 6,000 operating hours, 95% motor efficiency, 75% pump efficiency, and $0.06/kWh. Lifetime energy cost is the sum of the discounted value of annual energy costs based on a pump life of 15 years. Future electricity price trends and a discount rate of 3.4% are based on federal guidelines (effective from April 2000 to March 2001). b Lifetime energy cost is the sum of the discounted value of the annual energy costs based on average usage and assumed equipment life of 15 years. Source: United States Department of Energy’s Federal Energy Management Program (FEMP).
Table 2: Operating cost comparison: two flow control options for a 100-hp application a Performance
Flow control by throttling
Flow control by speed adjustment
Annual energy use
380,000 kWh
282,000 kWh
Annual energy cost
US$22,800
US$16,900
Lifetime energy cost b
US$239,000
US$177,000
Lifetime energy cost savings
-
US$62,000
a Assumes 6,000 operating hours, 95% motor efficiency, 75% pump efficiency, and $0.06/kWh. Future electricity price trends and a discount rate of 3.4% are based on federal guidelines (effective from April 2000 to March 2001). b Lifetime energy cost is the sum of the discounted value of the annual energy costs based on average usage and assumed equipment life of 15 years. Source: United States Department of Energy’s Federal Energy Management Program (FEMP)
26
www.worldpumps.com
efficiency to reduce costs, and the growing awareness of environmental considerations of poor use of energy sources. One could assume that these installations were planned for operating efficiency. However, the evidence suggests that the evaluation model used in determining the most appropriate installation is seriously flawed. Among the many reasons for the extreme inefficiency of so many pump installations was the common trend to oversize pumps and to use throttling valves. However, it could be argued that excessive use of throttling valves is not an efficient solution. It has been reported that throttling a valve by 50% significantly increases damage to the valve installation. The resulting loss is not only in efficiency but also in higher, unnecessary installation, maintenance and operating costs. One reason for this is might be the fact that the pumps represent as little as 15% of a total installation and there is too little consideration given to ongoing operating costs. The philosophy can be that ‘pumps are cheap – so put in larger pumps’, resulting in oversizing pumps which, for the most part, operate well below their optimum efficiency point. This practice was acceptable when energy costs were low at a time when little consideration was given to environmental issues. In today’s cost, energy and environmental climate, it is arguably not acceptable, and plant operators are looking increasingly at ways to reduce costs. “Do not focus so much on pumping efficiency but on total operating costs,” is the advice from Mogensen. “Technology is making the efficiencies even more achievable. Variable speed drive pumps are one way to reduce costs but a downfall of normal impellers is the tendency to clogging at lower frequency. This, for the most part, can be overcome by using vortex impellers. It is true that vortex impellers are not as efficient, but they enable significant energy saving, reduce clogging and are a much lower cost unit. So over the life of the pump, the option is viable.”
WORLD PUMPS July 2006
feature submersible pumps Although the PXPump range is available with variable speed drives, the company reportedly does not want to over-emphasise the availability because, it says, the market does not fully appreciate the benefits and only sees the risks. “Unfortunately, pump manufacturers have to supply customer demand, even though so many of us can see that what the customer is demanding is not necessarily the most cost effective solution, but customers have to go by what is specified in the contract,” says Morgenson. Variable speed drives (VSD), used in conjunction with advanced, more sophisticated, sensors, superior valve design and computer technology have enabled pump manufactures to develop intelligent pumps.By definition, intelligent pumps optimise performance to meet demand at the lowest possible cost. Gould Pumps, in a case study entitled Intelligent Variable Speed Pumping Controls Costs states: “Centrifugal pumps consume, depending on the industry, between 25% and 60% of electrical motor energy . . . In poorly designed systems, maintenance can be more than 40%.” The case study further explains the possible savings in energy that can be made through greater use of intelligent pumping. For instance, replacing throttling valves with speed controls can deliver a saving of anything up to 60%. It is not only manufacturers that are promoting better pump installation specifications. As governments come under increasing pressure to reduce the demand for energy, they are also helping utility companies look at ways to operate more efficiently. In a study called How to Buy an Energy-Efficient Centrifugal Pumping System, the United States Department of Energy’s Federal Energy Management Program (FEMP) analyses the cost efficiencies that could be achievable by implementing a modern approach to specifications and the costs of oversizing pumps. Table 1, on the left-hand page, illustrates the saving possible in energy costs alone.
WORLD PUMPS July 2006
The same study says that proper pump selection should consider both constant and variable flow and head conditions. In systems with little change in demand, pumping system efficiency depends largely on selecting the correct pump size, while in systems with variable demand, pump system efficiency depends on effectively matching supply with demand, which can be achieved in several ways, depending on system requirements. Many installations have to be designed to cope with variations in demands. These systems invariably have oversized pumps and throttling valves. Table 2 shows the cost saving possible by switching to variable speed drive systems. These are pure energy savings and do not take into account other operating costs which will provide further savings.
Specifiers are overly conservative Talking to pump manufacturers shows that many of them believe that consultants and other specifiers of pump installations too often use evaluation models that have not been updated for many years and which fail to take account of advances over the years and rising energy costs. “By over specifying the pumps required they minimise the risk of insufficient pumping capacity but introduce serious operating inefficiencies and excessive operating and maintenance costs,” says Mogensen. “With the modern range of pumps available today, there are ways to build in additional capacity, which enable the primary pumps to work at optimum efficiency. Not only is this a lower cost option, it is a greener solution as it minimises energy requirements.” To encourage specifiers and customers to modernise their conservatism, the company has introduced a modern range of pumps, which can be packaged in a variety of configurations. This enables a certain degree of customisation to meet specific
installation needs, whether the pumps are a replacement of existing units or for a new installation.
Getting the priorities right At the beginning of this article, we asked “Does the world need more submersible pumps – or better pumps and installations?” and the answer is probably far from straightforward because pumping efficiency is not taken seriously enough in many applications. Although pumps represent a very small part of the total cost of a new installation, manufacturers are nevertheless under increasing pressure to reduce costs. Unit cost could be said to be the driving force and encouraging companies to enter the pump market with inferior, albeit cheap pumps. “Most manufacturers are only too pleased to meet with specifiers and customers in determining the most efficient solution. Manu-facturers are often forced to provide the lowest cost solution based on pump cost,” says Mogensen. “If the specifiers and customers will allow us to show them how to size a pump for the best efficiency point (BEP) the operating costs are optimised. However, this can be complex and is often the reason for oversizing the pump. I am not confident that we can change attitudes quickly, which is why mine and other companies have to offer variations, which, ironically, increase production costs.” This attitude of specifiers and customers is also observed by the United States Department of Energy’s Federal Energy Management Program which states that the conservative practices often prioritize initial performance over system life cycle costs. As a result, larger-thannecessary pumps are specified, resulting in systems that do not operate optimally. Increased awareness of the costs of specifying oversized pumps could potentially discourage this tendency. ■
www.worldpumps.com 27