ASME EA-4–2010 pdf download.Energy Assessment for Compressed Air Systems.
capacitance: in compressed air systems, capability of a storage volume, primary receiver, dedicated use point re- ceiver, or other device for storing compressed air energy. Capacitance is expressed as the ratio of stored air volume (scf) to the storage pressure differential (psi). characteristic signature: dynamic prof le of airf ow rate and pressure changes with time that occurs during par- ticular production operations and compressed air de- mand events. compressed air system: a functional group of subsystems comprised of integrated sets of components, including air compressors, treatment equipment, controls, piping, pneumatic tools, pneumatically powered machinery, and process applications utilizing compressed air. control signal pressure: air pressure that is applied to the pressure switch, transducer, pilot valve, or other control device that creates an input signal to a compressor capac- ity control system. coverage interval: the interval (plus/minus percentage or minimum to maximum value) that, based on the infor- mation available, contains the true value of a parameter. The expression of coverage interval is associated with a specif ed conf dence level. data logging: measurement of physical parameters while tabulating a periodic log (record) of their numerical value using time-aligned data frames for the plurality of recorded parameters. dynamics: data logging while creating a suff ciently high frequency periodic log (record) so as to investi- gate the time-based variation of measured physical parameters. trending : data logging during an extended duration of time for the purpose of investigating commonality in the measured physical parameters throughout time.
end-to-end (measurement end-to-end): in measurement, includes the entire measurement system from the trans- ducer for the parameter to be measured to the record of the resultant value. equipment connection point: in compressed air piping, is at the inlet of the f rst control component associated with the point of use. That component may be a shut-off service or lock-out valve, a f lter/ regulator /lubricator combination, a solenoid control valve, or other control component. feasibility estimate (screening estimate): a statement of im- plementation cost that considers very little work has been done to def ne the project’s scope. Def ned as an ASTM Class 5 estimate, which considers <2% completion of the project def nition; by ASTM International E 2516-06, 2006 “Standard Classif cation for Cost Estimate Classif cation System.” f ow dynamic: situational operation of compressed air de- mands wherein the peak airf ow rate and minimum pres- sure must occur simultaneously. f ow static: situational operation of compressed air de- mands characterized when peak airf ow rate and mini- mum pressure required do not occur simultaneously. indirect measurement: a method to determine the value of a measured parameter that is done through the measure- ment of a suff ciently comprehensive group of related parameters so as to quantify the desired parameter. NOTES: (1) Methods may include stipulated values and assump- tions that allow the desired parameter to be deter- mined from indirect measurements.
sample rate (scan rate): indicates how fast a digital data acquisition system is making measurements of each individual input channel. Sample rate is expressed in terms of number of samples/unit of time (e.g., 10 sam- ples/min or 1 sample every 6 sec; higher speed sample rates may be expressed in Hz or kHz, e.g., 10-Hz sample rate). sector: a sector is a functional portion of a compressed air system that is a subset of the total system. Sectors may be segregated from the total system for purposes of delivered air quality, target pressure, priority, or other unique functional requirements. spot check measurement: measurement of physical param- eters creating a log (record) of their numerical value that is carried out at random time intervals or limited to a few instances. stipulated value: the value of a parameter based on as- sumption, reference to literature, calculation, etc. NOTE: A process for in-situ validation should conf rm that the stipulated value fairly represents the probable true value of the parameter. storage pressure differential: the difference between pres- sure in a storage volume and the desired target pressure of the connected system or sector. storage volume: the volume contained within a storage vessel (an air receiver tank) usually expressed in cubic feet or gallons (volume). target pressure: compressed air pressure that is desired to be consistently supplied to a compressed air system or sector of a compressed air system. It should be selected as the lowest possible pressure that allows for reliable operation of manufacturing processes. Typically target pressure is slightly greater than minimum system pres- sure (see also minimum system pressure).