CP Pump Systems Service Catalog

Fluid handling and rotodynamic pumping systems

Energy Efficient System Planning
Pumping systems are designed to meet many requirements, energy efficiency not always being one of them. As a result, some plants are built with poor system design where pumps are not properly matched to the system, pipe diameters are incorrectly sized and flow velocities are too high. Bad plant layout resulting in inefficient routing of pipes frequently exacerbates the situation as well. As all these factors increase frictional resistance, larger pumps than necessary are needed to deliver liquid to the required service.

• Calculation and design services providing clear and authoritative data to increase energy efficiency.
• Consulting and system analysis delivering clear and authoritative data to optimise energy consumption.

Existing systems
Changing a running system already in place is often difficult. Sometimes pumps, valves and measuring instruments are modified, for example to optimise a system’s available net positive suction head (NPSH), gather measurement information or change suction and/or discharge flanges, when retrofitting differently sized new pumps. Due to the heavy expenditure for engineering and materials, such modifications are usually limited in scale and often have little impact on the energy efficiency of an existing system.

One significant exception is to employ variable speed pumping solutions that can be retrofitted into a system already in service. Another viable option is to check whether any duty points can be subsequently rescaled, because each system is designed with safety margins added to the calculated system curves to ensure that sufficiently large pumps are selected for the job. As a result, the pumps installed are often oversized and then operate at excessive flow rates or in throttled conditions, increasing energy usage and reducing pump life.

New systems
Competent planning of new pumping systems to minimise energy consumption is one of the keys to reducing life cycle costs (LCC). Some energy use may not be output-dependent. For example, a control system sensing output changes may itself generate a constant energy load, whereas a variable speed drive can consume different levels of energy at different operating settings. Throttle valves, pressure relief mechanisms and flow bypasses used for control will all reduce operating efficiency and increase energy consumption. Additional costs may be caused by cooling or heating circuits, liquid flush lines or fluid barrier arrangements. While such costs often do not vary for different types of systems, they can be influenced by the selection of materials and designs.

Carefully selected pumping systems will reduce energy costs. A system’s overall frictional resistance can be minimised and the monetary savings maximised if attention is paid to the following points:

• Pumps must be optimally matched to the system in an early stage.
• Variable speed drives should be chosen, pipe diameters and distances correctly selected and flow velocities optimally designed for each position where they will help reduce energy consumption.
• Correctly determined pipe diameters and distances.
• Conveying speeds must be optimally aligned.

Energy efficient pumping and pump life cycle costs

Energy Efficient Pumps
Pumps are often selected according to technical and commercial specifications that do not sufficiently take into account life cycle costs (LCC). As a result, energy consumption is frequently one of the major cost components and may dominate the LCC, especially if pumps run more than 2,000 hours per year. A 1 kW power difference at the pump’s projected duty point can consume more than €10,000 worth of electricity over a 10-year operating life at 10 cent per kWh.

• Selection and specification of energy efficient pumps.
• Analysis and methodology to calculate the impact of energy efficient pumping systems and cut costs by reducing energy consumption.

Installed pumps
When pumps are already installed, you need to consider separate data showing the performance of each pump system over the output range. Performance can be measured in terms of the overall efficiency of the pump or the energy used by the system at the different output levels. Two important power requirements should be evaluated most carefully: the power consumption at the pump’s intended (rated) duty point and at its intended maximum flow rate. When pumps with high power consumption fail, many plant managers send them out to be repaired although the problem of energy wastage will not be solved. One solution is to adopt a pump management policy giving clear guidelines on when to purchase new pumps with minimal power requirements. As a rule, pumps with long running hours and those with larger motor sizes should be replaced. Pumps that run only occasionally and those with smaller motor sizes can be repaired. In case of doubt, asking your pump supplier for a quote indicating the above-mentioned power consumption at your duty point will help you find out how much your company could save with more efficient pumps. Sometimes, replacement of a fully functional pump can even be justified on energy grounds alone.

Selecting new CP pumps
Competent selection of new pumps to minimise energy consumption is one of the keys to reducing pump life cycle costs (LCC). Choosing sealless magnetic drive pumps over pumps with mechanical seals not only offers significant safety advantages; they often consume less energy as well, especially when fitted with non-metallic containment shells that eliminate eddy current losses. CP offers a wide range of different pump models and casings, containment shells and bearing materials to best suit the most diverse system requirements, while ensuring maximum safety and energy efficiency.

CP provides comprehensive advice to help you carefully select energy efficient CP pumps.