ASME EA-2G:2010 pdf download

ASME EA-2G:2010 pdf download.Guidance for ASME EA-2, Energy Assessment for Pumping Systems
1 General
1.1 Scope This guidance document provides an application guide on how to utilize ASME EA-2, Energy Assessment for Pumping Systems. This guidance document pro- vides background and supporting information to assist in applying the Standard. 1.2 Purpose ASME EA-2 does not provide guidance on how to perform a pumping system energy effciency assess- ment, but sets the requirements that must be performed during such an assessment. EA-2 was written in a form suitable for a standard, with concise text and without examples or explanations. This document was devel- oped to be used in conjunction with the standard to give basic guidance on how to fulfll the requirements of the standard. This document is only a guide and does not set any new requirements. ASME EA-2 can be used with or without this document.
2 introduction to PuMPinG SySteMS
2.1 overview Pumping systems are used widely worldwide to pro- vide cooling and lubrication services, to transfer fuids for processing, and to provide the motive force in hydraulic systems. In fact, most manufacturing plants, commercial buildings, and municipalities rely on pumping systems for their daily operation. In the manufacturing sector, pumping systems represent 27% of the electricity used by industrial systems. In the commercial sector, pump- ing systems are used primarily in heating, ventilation, and air-conditioning (HVAC) systems to provide water for heat transfer and water pressure boosting of domes- tic potable water. Municipalities use pumping systems for water and wastewater transfer and treatment and for land drainage. Since pumping systems serve such diverse needs, they range in size from fractions of a horsepower to several thousand horsepower.Pumping systems are essential to the daily operation of many facilities. This tends to promote the practice of oversizing pumps to ensure that the needs of the system will be met under all conditions. Intent on ensuring that the pumps are large enough to meet system needs, engi- neers who design pumping systems often overlook the cost of oversizing pumps and add more pump capac- ity than is necessary. Unfortunately, this practice results in higher-than-necessary system operating and main- tenance costs. In addition, oversized pumps typically require more frequent maintenance than properly sized pumps. Excess fow energy increases the wear and tear on system components, often resulting in valve damage, piping stress, and excess system operation noise. It is important to keep in mind that pumping systems are often parts of larger systems, such as complex indus- trial processes or HVAC systems. Therefore, potential impacts on the larger systems should be considered when evaluating pumping systems.
Many factors are involved in the selection of appro- priate pump technology. Primary among these are fuid characteristics and process requirements, but economics and experience also play important roles. Certain appli- cations can be served by either positive displacement or centrifugal pumps, but since low viscosity fuids, for which centrifugal pumps are ideally suited, dominate process, commercial, and waste/water applications, centrifugal pumps are more common. When properly applied they are simple, safe to operate, and provide acceptable operating life. Centrifugal pumps are also available in high fow rate designs and in systems that may be oversized, therefore making them prime candidates for energy assessments. Positive displacement pump designs are typically fow rate limited, and although a variety of fuids can be handled by available confgurations, they are most frequently applied on viscous or specialty fuid appli- cations. They further vary from centrifugal pumps by having the characteristic of constant fow rate at con- stant speed, and in properly designed systems require some pressure limiting device. Performance characteris- tics are best considered within the technology subcate- gories that are (a) rotary: screw, gear, vane, lobe, fexible member, progressing cavity (b) reciprocating: piston, diaphragm