ASME EA-2G-2010 pdf free

ASME EA-2G-2010 pdf free.Guidance for ASME EA-2, Energy Assessment for Pumping Systems.
Further, some applications have flow and fluid characteristics that warrant consideration of LD versus centrifugal technology based on comparison of system efficiencies.
Centrifugal pumps have a variable flow/pressure relationship. A centrifugal pump acting against a highsystem pressure generates less flow than it does when acting against a low-system pressure. A centrifugal pump’s flow/pressure relationship is described by a performance curve that plots the head (pressure) as a function of flow rate. Understanding this relationship is essential to sizing a pump properly and designing a pumping system that performs efficiently. For more information, see references 121 and 131 in Nonmandatory Appendix A.
2.2.2 Prime Movers. Most pumps are driven by electric motors. Although some pumps are driven by direct current (dc) motors, the low cost and high reliability of alternating current (ac) motors make them the most common type of pump prime mover. Energy- efficient motors are standard in today’s marketplace, and “premium efficiency” motors are widely available in common sizes and enclosures. In high run-time applications, improved motor efficiencies can significantly reduce operating costs. However, the assessment’s focus should typically be on a systems approach, where attention to systems issues such as component sizing, piping configuration, and maintenance practices typically identifies the greatest energy savings opportunities. A high efficiency motor usually operates at a higher speed than an older, less efficient motor. The pump might therefore create higher pressure and flow and consume more energy if no other changes are made to the system. When changing to a more efficient motor, system effects should therefore be taken into account.
Steam turbines and other devices, although much less common, are also used to power pumping systems.
2.2.3 Piping. Piping is used to contain the fluid and carry it from the pump to the point of use. The critical aspects of piping are its dimensions, material type, and cost. Since all three aspects are interrelated, pipe sizing is an iterative process. The flow resistance of a pipe at a specified flow rate is highly dependent on pipe size, and decreases as the pipe diameter gets larger. For example, increasing pipe diameter by 1O’Y0 can result in a pressure drop of more than 60%. However, larger pipes are heavier, take up more floor space, and cost more than smaller pipe. Similarly, in systems that operate at high pressures (for example, hydraulic systems), small-diameter pipes can have thinner walls than large-diameter pipes and are easier to route and install.
Small-diameter pipes restrict flow, however, and this can be especially problematic in systems with surging flow characteristics. Smaller pipes also operate at higher liquid velocity, increasing erosion effects, wear, and friction head. Increased friction head affects the energy required for pumping.ASME EA-2G pdf download.