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ISLLI S S To obtain satisfactory operation froma Lake pneumatic flow rate monitor, the following points should be con- sidered:

Pneumatic Flow Meter Uses and Theory - 13808 Pneumatic Monitor Uses and Operating TheoryPneumatic Monitor Uses and Operating Theory

Flow ange Method 1
1 Estimating the flow rate in a com-pressed gas system may seem com- plicated, but with some research and a few simple equations an educated guess can be made. Two suggested methods are: A compressor is typically rated inSCFM output at a certain pressure and efficiency. If the rating cannot be located or is unknown, an estimate of compressor output can be obtained by the following formulas: P P
â—† install a pressure gauge near the inlet of the monitor
â—† place throttling valves at the outlet of the monitor
â—† use pipe sealer on the connections
â—† install a union on one side of the monitor for easy removal for maintenance and calibration
â—† 1-stage compressors :motor P/0.179 SCFM 100 PSIG
â—† install solenoid valves at the monitor outlet (as far down- stream as possible) P P
â—† -stage compressors :motor P/0.14 SCFM 100 PSIG
â—† mount in any orientation: verti- cal, horizontal or upside down
â—† -stage compressors :motor P/0.159 SCFM 100 PSIG
â—† install restrictions between pressure gauges and the monitor inlet Method If all of the potential of a compressoris not being used (the unit cycles on and off) or if flow rate in excess of compressor capacity is being consumed (the compressor cannot meet the demand), a summation of machine usages can be totaled to determine the maximum flow rate. Most machine tools that use com- pressed air specify the maximum consumption of the tool.
â—† install solenoid valves at the monitor inlet
â—† place restrictions between the monitors pressure gauge and the monitor inlet
â—† use in systems where reverse flow is possible
â—† place monitor in non-aligned piping P P
â—† over-flow the monitor by more than 10% of maximum reading
â—† operate at pressures and temper- atures greater than specified

ensity Correction Factors

SCFM (indicated) (CF) SCFM (actual) CF (f1) (f2) (f3) Note: all correction factors need not be used. Table 1. f1 PSS CCI FCS (inlet pressure) psig 25 50 75 100 125 150 175 200 f1.5 .75 .88 1.0 1.11 1.2 1.29 1.37 Table 2. f1 14.7 psig114.7 f MP CCI FCS FIGURE 1. ºF 10º 30º 50º 70º 90º 110º 130º 150º f21.08 1.04 1.02 1.0 .98 .9 .95 .93 Table 3. f2 53040 F A diagram illustrating the effect ofdifferent pressures on the volumn of gas.
f SPCIFIC GI CCI FC f1 correction factor for other than 100 PSI inlet.f2 correction factor for other than 70º F.f3 correction factor for other than air at 1.0 Sp. Gr. f3 1Sp. Gr. LAE MNITRS, 2013 South 37th Street, Milwaukee, WI 53215414.71.3577 / 800.850.110 / Fax: 414.71.5253 GOTDS-404 7.5M CK / WGD / MAS © Lake Monitors Inc. 2004

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