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C =
C =
C =
C = COMPRESSOR CAPACITY IN CFM
V = RECEIVER & PIPING VOLUME IN CU. FT.
P2 = FINAL CUT OUT PRESSURE PSIA= 100 PSIG + 14.7 = 114.7 PSIA
P1 = INITIAL PRESSURE PSIA= 70 PSIG + 14.7 = 84.7 PSIA
V (P2- P1) 60 SEC.(14.7) (TIME-SEC.)
* Assume the receiver and piping volume were 80 cu. ft.* Assume the pump-up time is 15 seconds.
Then solve:
(80) (114.7 - 84.7) (60)(14.7) (15)
144,000220.5
C = 653 cubic ft./min. = actual capacity of existing air compressor
1
DETERMINING YOURAIR REQUIREMENTS
A relatively simple procedure to see if additional compressor capacity(CFM) is required can be performed in any plant or compressedair-using operation.
Most general compressor air operations supply 100 PSIG at thecompressor and deliver a minimum of 90 PSIG to the using air tool. For
lowest possible power cost, this means compressor has a cut outpressure or unloads at 100 PSIG and cut-in or loads at 90 PSIGreceiver or system pressure. With these known figures (or whateverunload and load figures a particular system utilizes), we can determinethe following:
If the receiver is below the normal cut-in point (90 PSIG) or does notgradually rise to the cut-out point (100 PSIG), more air is probablyneeded. Always check, of course, that there are no significant leaksand that the unloading and control system on the compressor arefunctioning correctly.
NOTE: If the compressor must operate at more than 100 PSIG to get90 PSIG at the tools, check the distribution system for piping size or
check points. The pipe may be too smallor a single choke point toosmallfor the systems total demand (flow) or length.
CHECKING EXISTINGCOMPRESSOR CAPACITY
Running a timed pump-up test is a relatively accurate way to checkyour existing air compressors capacity or output. This will confirm thatyour shortage of compressed air is not due to a worn unit or amalfunction.
Check the receiver volume in cubic feet. Check the pipe volumebetween the compressor and receiver in cubic feet. Operate thecompressor at load. Close the air valve between the receiver and plantair system. Drain the receiver down to 70 PSIG. Close the drain valvequickly. Record in seconds the required time to pump to 100 PSIG.
Now work the following equation:
If this is close to the rated capacity of your air compressor, then you canbe relatively sure the demand on your air system is too high and youneed additional air.
28
GENERAL TERMS CONTINUED
PISTON DISPLACEMENT:
Is the volume swept by the piston, generally expressed in cubic feet per
minute (CFM). For multi-stage compressors, the piston displacementof the first stage only is commonly stated as that of the entire machine.
ACTUAL CAPACITY:
Is the quantity of gas actually compressed and delivered to thedischarge system by the compressor at rated speed and under rated
pressure conditions. Actual capacity is expressed in cubic feet perminute at the temperature and pressure conditions existing at the inlet
to the first stage.
VOLUMETRIC EFFICIENCY:
Is the ratio of actual capacity to piston displacement, generally stated
as percentage.
FREE AIR:
Generally describes air at room or ambient temperatures and pressures,that is, normal atmospheric conditions. In other words, the term free airdescribes the air actually taken into the suction of a compressor which
takes air from the surrounding atmosphere.
STANDARD CONDITIONS:
Are not universally defined; therefore, since compressor capacities are
sometimes expressed in standard cubic feet per minute (SCFM), it isnecessary to identify, before the compressor can be sized, (1) the
standard pressure condition; (2) the standard temperature condition;
(3) the compressor suction pressure condition, and; (4) thecompressor suction temperature condition. The most popular
identification for standard pressure and temperature conditions is 14.5
PSIA or 60F.
BRAKE HORSEPOWER (bhp):
Is the measured horsepower input at the compressor shaft. Thehorsepower output of the driver must equal or exceed the compressor
bhp plus any drive losses.
LOAD FACTOR:
Is the ratio of the available demand for compressed air during a certainperiod of time to the maximum rated output capacity of the compressor.
NOTES:
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TERMINOLOGY CONTINUED
UNLOAD (No Load):Air compressor continues to run (usually at FULL RPM), but NO air isdelivered because intake is either closed off or modified, NOT allow-ing inlet air to be trapped.
MODULATING UNLOAD:Air compressor continues to run and air supply is matched to demand
by partial unloading. This is usually accomplished by a regulatorcontrolled floating inlet.
START-STOP CONTROL:Air supply is matched to demand by actual starting and stopping of theunit.
CUT-IN/CUT-OUT PRESSURE:The settings on a pressure switch used to either load or unload the aircompressor on constant speed application. The cut-out pressure isalso referred to as maximum pressure, the point at which there is NOAIR DELIVERED. The cut -in pressure is also referred asminimum pressure - the pressure that the system is allowed to fall tobefore additional air volume is called for. The compressor runs at fullload between cut-in and cut-out.
VARIABLE DISPLACEMENT CONTROLS:Also called Rotor Length Adjustment in oil cooled Rotary Screwcontrols. Particularly efficient in holding constant speed from 60% to100% capacity variable speed control. Below this usually goes to blowdown and idle.
VARIABLE SPEED CONTROL:
Most commonly applied in oil cooled Rotary Screws. Very efficient fromabout 50% to 100% capacity. Below 50% usually defaults to modula-tion of Blow Down and idle.
RATED PRESSURE:The operating pressure at which the air compressors performance (CFMand BHP - Horsepower required) is measured.
SPECIFIC POWER:Used to compare air compressor efficiency unless otherwise stated.Usually in form of BHP/100 ACFM or CFM/HP.
GENERAL TERMS
COMPRESSORS:Are machines which compress air or gases from atmospheric pressureto a higher discharge pressure.
BOOSTER COMPRESSORS:Are machines which compress air or gases from a pressure higherthan atmospheric to a still higher discharge pressure.
VACUUM PUMPS:
Are machines designed for compressing air or gases from an initialpressure which is below atmospheric to a pressure which is at or closeto atmospheric pressure.
RECIPROCATING COMPRESSORS:Are positive displacement machines used to increase the pressure of adefinite volume of gas by volume reduction. The compressing elementis a simple piston which reciprocates back and forth in a cylinder.
COMMON LEAK PROBLEM AREAS
COUPLINGS, HOSES, TUBES AND FITTINGS Tubes and push-to-lock fittings are common problems.
DISCONNECTS O-rings required to complete the seal may be missing.
FILTERS, REGULATORS AND LUBRICATORS (FRLs)
Low first-cost improperly installed FRLs often leak.OPEN CONDENSATE TRAPS Improperly operating solenoids and dirty seals are often problem
areas.
PIPE JOINTS Missed welds are a common problem.
CONTROL AND SHUT-OFF VALVES Worn packing through the stem can cause leaks.
POINT OF USE DEVICES Old or poorly maintained tools can have internal leaks.
FLANGES Missed welds are a common problem.
CYLINDER ROD PACKING Worn packing materials can cause leaks.
THREAD SEALANTS Incorrect and/or improperly applied thread sealants cause leaks.
HOW DO YOU FIND LEAKS?
Since air leaks are almost impossible to see, other methods must beused to locate them. The best way to detect leaks is to use anultrasonic acoustic detector, which can recognize the high frequencyhissing sounds associated with air leaks. These portable units consistof directional microphones, amplifiers, and audio filters, and usuallyhave either visual indicators or earphones to detect leaks. A simplermethod is to apply soapy water with a paint brush to suspect areas.Although reliable, this method can be time consuming. Other methodsinclude: smoke sticks, candles, foam, manometers and stethoscopes.
Ultrasonic detectors can find mid to large sized leaks. The advantagesof ultrasonic leak detection include: versatility, speed, ease of use, theability to perform tests while equipment is running and the ability to find
a wide variety of leaks.
HOLE DIA. AIR LEAKAGE AT 100 PSI COST PER YEARIN. CFM $.06 KWH
1/32 1.62 $1581/16 6.5 $6331/8 26 $2,5321/4 104 $10,130
WHAT DO SYSTEM LEAKS COST?
Determine size of leak either through calculation or actual size oforifice.
1/4inch orifice can pass 104 CFM @ 100 PSIG.
A typical 25 horsepower oil flooded Rotary Screw Air Compressor.
At 6 cents a kW and 8,000 hours of operation, this can equal$9,946.00.
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USEFUL FORMULAS
1. COMP. RPM =
2. MOTOR PULLEY p.d. =
3. COMP. PULLEY p.d. =
4. MOTOR RPM =
5. FREE AIR = piston displacement x volumetric eff. (%)
=
=
=
=
=
= x
=
motor pulley p.d. x motor RPMcomp. pulley p.d.
comp. pulley p.d. x comp. RPMmotor RPM
motor pulley p.d. x motor RPMcomp. RPM
comp. pulley p.d. x comp. RPMmotor pulley p.d.
6. REQUIRED PISTON free air DISPLACEMENT vol. eff.
7. PISTON DISPLACE- Cyl. bore x Cyl. bore x stroke in In. x RPM
MENT IN CU.FT. MIN* 2200
8. CU. FT. COM- cu. ft. free air x atmospheric pressurePRESSED AIR (PSIG + 14.7)
9. CU. FT. cu. ft. compressed air x (PSIG + 14.7)FREE AIR atmospheric pressure
10. CU. FT. FREE AIRREQD TO RAISE vol. of rec. in cu. ft. x PSIGREC. FROM 0 GAUGE atmospheric pressure
TO FINAL PRESSURE
11. CU. FT. FREE AIR
REQD TO RAISE REC.
FROM SOME PRESS. vol. of rec. (final PSIG init ial PSIG)
GREATER THAN 0 in cu. ft. (atmospheric pressure)
GAUGE TO A FINAL
HIGHER PRESSURE
12. PISTON SPEED IN 2 x stroke ( in inches) x RPMFT. PER MIN. 12
13. GALLONS =
14. CU. FT. = gallons x .134
15. TOTAL FORCE INLBS. OF AIR = xCYLINDER
16. CFM OF FREEAIR REQUIRED
TO OPERATE = x xAIR CYLINDER(SINGLE ACTING)
For Double Acting Cylinders Multiply by 2.
* Piston displacement for multi-stage compressors - only the lowpressure cylinder is considered.
cu. ft..134
Area of Cylinder PSIG of airDia. in sq. inches press. used
Vol. of Cyl. Cycles (Gauge Press. + 14.7)in cu. ft. per min. (14.7)
524
INDUSTRIAL TOOLS & EQUIPMENT
AIR AVG. FREE NORMALPRESSURE EQUIPMENT AIR CONS. LOAD
RANGE CFM FACTOR**
Always check with tool manufacturers for actual consumption of tools being used.The above are based on averages and should not be considered accurate forany particular make of tools. The free air consumptions listed herein are basedon the use of the normal load factors shown in the adjacent column. Load factoris a percentage that expresses the normal actual usage of air as compared tothe maximum usage that will occur if the tools throttle valve is turned fully openand the tool is operated continuously at maximum capacity (Load factors shouldbe adjusted based on your own individual operating conditions).
ANTICIPATING YOURFUTURE AIR REQUIREMENTS
The following charts will be helpful to anyone planning a future air system orrequirement. Remember, these are averages for various types of tools and youshould always consult the manufacturer for exact air requirements and analyzeyour own operation to evaluate normal.
90-100 *Dusting Gun (Blow Gun) 3.0 10%90-100 *Drill, 1/6 to 1/8 4.0 25%90-100 *Drill, 3/8 to 5/8 7.0 25%
90-100 *Screwdriver, #2 to #6 Screw 1.0 15%90-100 *Screwdriver, #6 to 5/16 Screw 3.0 15%90-100 *Tapper, to 3/4 3.0 15%
90-100 *Nutsetters, to 3/8 3.0 15%90-100 *Nutsetters, to 3/4 5.0 15%90-100 *Impact Wrench, 3/8 sq.dr. 2.0 20%
90-100 *Impact Wrench, 1/2 sq.dr. 3.5 20%90-100 *Impact Wrench, 5/8 sq.dr. 5.0 20%90-100 *Impact Wrench,3/4 sq.dr 7.5 20%90-100 *Impact Wrench, 1 sq.dr. 10.0 20%
90-100 *Die Grinder, Small 4.0 30%90-100 *Die Grinder, Medium 5.0 30%90-100 *Horizontal Grinder, 2 10.0 30%90-100 *Horizontal Grinder, 4 14.0 30%90-100 *Horizontal Grinder, 6 16.0 30%90-100 *Horizontal Grinder, 8 20.0 30%90-100 *Vertical Grinders & Sanders,
5 Pad 10.0 30%90-100 *Vertical Grinders & Sanders,
7 Pad 14.0 30%90-100 *Vertical Grinders & Sanders, 9 Pad 20.0 30%
90-100 *Filing & Sowing Mach., small 3.0 15%90-100 *Filing & Sowing Mach., large 5.0 15%
90-100 *Burring Tool, small 4.0 30%90-100 *Burring Tool, large 5.0 30%
90-100 *Bench Rammer 5.0 40%90-100 *Floor Rammer 7.0 40%90-100 *Backfill Tamp 15.0 40%
90-100 *Compression Riveter 1.0 10%90-100 *Automatic Drills 6.0 25%
90-100 *Air Motor, 1 HP 10.0 25%90-100 *Air Motor, 2 HP 15.0 25%90-100 *Air Motor, 3 HP 20.0 25%90-100 *Air Motor Hoist, 1000# 5.0 10%90-100 *Air Motor Hoist, 2000# 5.0 10%90-100 *Cylinder Type Hoist 1.5 10%
HAMMERS
90-100 *Scaling Hammer 4.0 35%90-100 *Chipping Hammer 7.0 35%90-100 *Riveting Hammer 15.0 35%
SPRAY GUNS
90-100 *Point Spray Gun (Production) 8.5 50%90-100 *Point Spr ay Gun (Touch-up) 3.5 25%
* ORIFICES ARE REQUIRED
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15
15
15
15
15
20
30
45
60
80
90
100
110
15
0
200
225
250
350
450
600
800
4
5.6
8
10
10
15
25
30
40
60
80
100
100
15
0
200
200
300
350
400
500
600
722
14 x 33 20 2.7 12.0 20.8 25.3 30.0 34.4 38.9
16 x 38 30 4.0 18.0 31.2 38.0 45.0 51.6 58.4
20 x 48 60 8.0 36.0 62.4 76.0 90.0 103.2 116.8
20 x 63 80 10.7 48.0 83.2 101.3 120.0 137.6 155.7
24 x 67 120 16.0 72.0 1 24.8 1 52.0 1 80.0 2 06.4 2 33.6
30 x 8 4 240 32 .0 14 4.0 2 49.6 3 04 .0 3 60.0 412 .8 4 67.2
50 1.8 5.0 10.1 18.1
60 1.3 4.0 8 .4 14.8 23.4
70 1.0 3.4 7.0 12.4 20.0 28.41/2 80 0.9 2.8 6.0 10.8 17.4 25.2 34.6
90 0.8 2.4 5.4 9.5 14.8 22.0 30.5 41.0
100 0.7 2.3 4.8 8.4 13.3 19.3 27.2 36.6
110 0.6 2.0 4.3 7.6 12.0 17.6 24.6 33.3 44.5
50 0.4 0.8 1.5 2.4 3 .5 4.4 6 .5 8.5 11.4 14.2
60 0.3 0.6 1 .2 1.9 2.8 3 .8 5.2 6 .8 8.6 11.2
70 0.2 0.5 0 .9 1.5 2.3 3 .2 4.2 5 .5 7.0 8.8 11.0
3/4 80 0.2 0.5 0.8 1.3 1.9 2.8 3.6 4.7 5.8 7.2 8.8 10.6
90 0.2 0.4 0 .7 1.1 1.6 2.2 3 .1 4.0 5.0 6.2 7.5 9.0
100 0.2 0.4 0 .6 1.0 1.4 2.0 2.7 3.5 4.4 5.4 6.6 7.9
110 0.1 0.3 0.5 0.9 1 .3 1.8 2.4 3.1 0.9 4.9 5.9 7.1
50 0.1 0.2 0 .3 0.5 0.8 1 .1 1.5 2.0 2.6 3.5 4.8 7.0
60 1.1 0.2 0 .3 0.4 0.6 0.8 1.2 1.5 2.0 2.6 3.3 4.2
70 -- 0.1 0.2 0.4 0.5 0.7 1.0 1.3 1.6 2.0 2.5 3.1
1 80 -- 0.1 0.2 0.3 0.5 0.7 0.8 1.1 1.4 1.7 2.0 2.4
90 -- 1.1 0 .2 0.3 0.4 0.6 0.7 0.9 1.2 1.4 1.7 2.0
100 -- 1.1 0.2 0.2 0.4 0.5 0.6 0.8 1.0 1.2 1.5 1.8
110 -- 0.1 0.2 0.2 0.3 0.4 0.6 0.7 0.9 1.1 1.3 1.5
FRICTION OF AIR IN HOSE
HOSE
SIZE
GAUGE CU. FT. OF AIR PER MINUTE AT 80 PSIG
PRESSURE 20 30 40 50 60 70 80 90 100 110 120 130
OF LINE LOSS OF PRESSURE (PSI) IN 50 FT. LENGTHS OF HOSE
These devices are to be considered as continuously operating deviceswhen operating normally. All other devices listed are to be consideredas intermittently operated when operating normally. When the devicesconsist of a large number of the continuously operated type, and if only afew are to be used at one time, the compressor should have a capacityat least equal to the total consumption of all those tools usedsimultaneously, in addition to the consumption of all the intermittentlyoperated tools, if any.
**Normal load factor is the percentage of time the throttle valve is openduring normal use.
COMPRESSED AIR RECEIVERCAPACITY
CAPACITYIN
GALLONS
TANKDIMENSION
CAPACITY IN CU.FT. OF FREE AIRAT GAUGE PRESSURE SHOWN
0 50 100 125 150 175 200
THREEPHAS
EMOTOR
DATA
-Fo
r60Hz1800RPMS
tandardMotor
MOTOR
1/2
3/4
1
11/2
2
3
5
71/2
10
15
20
25
30
4
0
50
60
75
100
125
150
200
15
15
15
15
15
20
35
50
60
90
100
110
125
17
5
200
250
300
400
600
600
800
4
6.25
8
10
10
17.5
25
40
50
60
90
100
125
17
5
200
250
300
400
500
600
--
MOTOR
SYSTEM
200V
(208V)
MOTOR
SYSTEM
230V
(240V)
2.5
3.7
4.8
6.9
7.8
11.0
17.5
25.3
32.2
48.3
62.1
78.2
92
12
0
150
177
221
2853
59
414
552
14
14
14
14
14
14
12
10
8
6
4
3
2
1/
0
3/0
4/0
300
5002
-4/0
2-300
2-500
2.2
3.2
4.2
6.0
6.8
9.6
15.2
22
28
42
54
68
80
10
4
130
154
192
248
312
360
480
14
14
14
14
14
14
14
10
10
6
4
4
3
1
2/0
3/0
250
3502
-3/0
2-4/0
2-350
FULLLOADCURREN
T
(NEC)-AMPSMINIM
UM
COPPERWIRESIZE-
(75C)THW,THHN-
THWN,XHHW-SIZE
CIRCUITBREAKER
Thermal-MagneticBre
aker
TripRating-AMPS
FUSIBLESWITCH
WithDualElementTi
me
DelayFuse-AMPS
FULLLOADCURREN
T
(NEC)-AMPSMINIM
UM
COPPERWIRESIZE-
(75C)THW,THHN-
THWN,XHHW-SIZE
CIRCUITBREAKER
Thermal-MagneticBre
aker
TripRating-AMPS
FUSIBLESWITCH
WithDualElementTi
me
DelayFuse-AMPS
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W =
Table is based on 100% coefficient of flow. For well rounded entrance, multiply valuesby 0.97. For sharp edged orifices a multiplier of 0.61 may be used for approximateresults. Values for pressures from 1 to 15 lbs. gauge calculated by standard adiabaticformula. Values for pressures above 15 lbs. gauge calculated by approximate formulaproposed by S.A.
Moss. Where:
0.5303 ACp1 W = discharge in lbs. per sec. T1 A = area of orifice in sq. in.
C = Coefficient of flow
P1 = Upstream total pressure in lbs. per sq. in absolute
T1 = Upstream temperature inF abs.
Values used in calculating above table were:
C = 1.0, p1= gauge pressure + 14.7 lbs./sq. in.
T1 = 530 F abs.
Weights (W) were converted to volumes using density factor of 0.07494 lbs./cu. ft. This iscorrect for dry air 14.7 lbs. per sq. in. absolute pressure and 70
F. Formula cannot be usedwhere p1 is less than two times the downstream pressure.
20 9
DIAMETER OF ORIFICE
1/64 1/32 1/16 1/8 1/4 3/8 1/2 5/8 3/4 7/8 1
Discharge in cubic feet of free air per minute1 .028 .112 .450 1.80 7.18 16.2 28.7 45.0 64.7 88.1 115
2 .040 .158 .633 2.53 1 0.1 22.8 40.5 63.3 91.2 124 162
3 .048 .194 .775 3.10 12.4 27.8 49.5 77.5 111 152 198
4 .056 .223 .892 3.56 14.3 32.1 57.0 89.2 128 175 228
5 .062 .248 .993 3.97 15.9 35.7 63.5 99.3 143 195 254
6 .068 .272 1.09 4.34 17.4 39.1 69.5 109 156 213 278
7 .073 .293 1.17 4.68 18.7 42.2 75.0 117 168 230 300
9 .083 .331 1.32 5.30 21.2 47.7 84.7 132 191 260 339
12 .095 .379 1.52 6.07 24.3 54.6 97.0 152 218 297 388
15 .105 .420 1.68 6.72 26.9 60.5 108 168 242 329 430
20 .123 .491 1.96 7.86 31.4 70.7 126 196 283 385 503
25 .140 .562 2.25 8.98 35.9 80.9 144 225 323 440 575
30 .158 .633 2.53 10.1 40.5 91.1 162 253 365 496 648
35 .176 .703 2.81 11.3 45.0 101 180 281 405 551 720
40 .194 .774 3.10 12.4 49.6 112 198 310 446 607 793
45 .211 .845 3.38 13.5 54.1 122 216 338 487 662 865
50 .229 .916 3.66 14.7 58.6 132 235 366 528 718 938
60 .264 1.06 4.23 16.9 6 7.6 152 271 423 609 828 1082
70 .300 1.20 4.79 19.2 76.7 173 307 479 690 939 1227
80 .335 1.34 5.36 21.4 85.7 193 343 536 771 1 050 1371
90 .370 1.48 5.92 23.7 94.8 213 379 592 853 1161 1516100 .406 1.62 6.49 26.0 104 234 415 649 934 1 272 1661
110 .441 1.76 7.05 28.2 113 254 452 705 1016 1383 1806
120 .476 1.91 7.62 30.5 122 274 488 762 1097 1494 1951
125 .494 1.98 7.90 31.6 126 284 506 790 1138 1549 2 023
150 .582 2.37 9.45 37.5 150 338 600 910 1315 1789 2338
200 .761 3.10 12.35 49.0 196 441 784 1225 1764 2401 3136
250 .935 3.80 15.18 60.3 241 542 964 1508 2169 2952 3856
300 .995 4.88 18.08 71.8 287 646 1148 1795 2583 3515 4592
400 1.220 5.98 23.81 94.5 378 851 1512 2360 3402 4630 6048
500 1.519 7.41 29.55 117.3 469 1055 1876 2930 4221 5745 7504
750 2.240 10.98 43.85 174.0 696 1566 2784 4350 6264 8525 111361000 2.985 14.60 58.21 231.0 924 2079 3696 5790 8316 11318 14784
DISCHARGE OF AIRTHROUGH AN ORIFICE
In cubic feet of free air per minute at standard atmospheric pressure of14.7 lb. per sq. in. absolute and 70F
GAUGEPRESSURE
BEFOREORIFICEIN LBS.
PER
SQ.IN.
FRICTIONLO
SSOFAIRIN
PIPE-
PRESSURELOSSIN
POUNDSFOREAC
H100FEETOFSTR
AIGHTPIPE
CONTINUED
300
.36
.30
.26
.20
.16
.13
.10
500
.94
.78
.67
.52
.43
.36
.26
.20
.17
.14
.11
750
1.6
9
1.4
4
1.1
2
.92
.78
.56
.44
.36
.30
.23
.19
.16
.14
1000
2.5
0
1.9
4
1.5
9
1.3
4
.97
.76
.62
.53
.41
.33
.28
.24
1500
4.3
0
3.5
2
2.9
8
2.1
5
1.6
8
1.3
8
1.1
7
.90
.73
.61
.53
2000
5.2
9
3.8
1
2.9
9
2.4
7
2.0
8
1.6
0
1.3
0
1.0
9
.94
2500
5.9
6
4.6
7
3.8
3
3.2
6
2.5
0
2.0
2
1.7
0
1.4
7
3000
8.5
8
6.7
1
5.5
1
4.6
8
3.5
8
2.9
1
2.4
5
2.1
1
3500
9.1
5
7.5
0
6.3
7
4.8
9
3.9
6
3.3
4
2.8
8
4000
11.9
9.8
0
8.3
1
6.3
6
5.1
6
4.3
5
3.7
6
4500
12.4
10.5
8.0
6
6.5
5
5.5
0
4.7
5
5000
15.3
13.0
9.9
5
8.0
7
6.8
0
5.8
6
6000
14.3
11.6
9.7
8
8.4
5
7000
19.5
15.9
13.4
11.5
3
SCHEDULE
40
NOMINAL
CFM
PIPESIZE
FREEAIR
LINEPRESSURE-PSIG
10
15
20
30
40
50
75
100
125
150
200
25
0
300
350
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50
1.8
5.0
10.1
18.1
60
1.3
4.0
8.4
14.8
23.4
70
1.0
3.4
7.0
12.4
20.0
28.4
80
0.9
2.8
6.0
10.8
17.4
25.2
34.6
90
0.8
2.4
5.4
9.5
14.8
22.0
30.5
41.0
100
0.7
2.3
4.8
8.4
13.3
19.3
27.2
36.6
110
0.6
2.0
4.3
7.6
12.0
17.6
24.6
33.3
44.5
50
0.4
0.8
1.5
2.4
3.5
4.4
6.5
8.5
11.4
14.2
60
0.3
0.6
1.2
1.9
2.8
3.8
5.2
6.8
8.6
11.2
70
0.2
0.5
0.9
1.5
2.3
3.2
4.2
5.5
7.0
8.8
11.0
80
0.2
0.5
0.8
1.3
1.9
2.8
3.6
4.7
5.8
7.2
8.8
10.6
90
0.2
0.4
0.7
1.1
1.6
2.3
3.1
4.0
5.0
6.2
7.5
9.0
100
0.2
0.4
0.6
1.0
1.4
2.0
2.7
3.5
4.4
5.4
6.6
7.9
9.4
11.1
110
0.1
0.3
0.5
0.9
1.3
1.8
2.4
3.1
3.9
4.9
5.9
7.1
8.4
9.9
50
0.1
0.2
0.3
0.5
0.8
1.1
1.5
2.0
2.6
3.5
4.8
7.0
60
1.1
0.2
0.3
0.4
0.6
0.8
1.2
1.5
2.0
2.6
3.3
4.2
5.5
7.2
70
--
0.1
0.2
0.4
0.5
0.7
1.0
1.3
1.6
2.0
2.5
3.1
3.8
4.7
80
--
0.1
0.2
0.3
0.5
0.7
0.8
1.1
1.4
1.7
2.0
2.4
2.7
3.5
90
--
1.1
0.2
0.3
0.4
0.6
0.7
0.9
1.2
1.4
1.7
2.0
2.4
2.8
100
--
1.1
0.2
0.2
0.4
0.5
0.6
0.8
1.0
1.2
1.5
1.8
2.1
2.4
110
--
0.1
0.2
0.2
0.3
0.4
0.6
0.7
0.9
1.1
1.3
1.5
1.8
2.1
11
FRICTION
OF
AIRIN
HOSE-
Puls
ating
Flow
*
18
1/2
3/4
1
CU.F
T.FREEAIRP
ERMIN.
PASSINGTHROUGH
50FT.LENGTHSOFHOSE
20
30
40
50
60
70
80
90
100
110
120
130
140
150
LOSSOFPRESSURE(PSI)IN50FT.LE
NGTHSOFHOSE
SIZEOFHOSE,
GAUGE
COUPLED
P
RESSURE
EACHEND,IN.
A
TLINE,LB.
FRICTION
LO
SSOFAIRIN
PIPE-
PRESSURELOSSIN
POUNDSFOREAC
H
100FEETOFSTR
AIGHTPIPE
CONTINUED
75
.19
.16
.13
.10
100
.28
.24
.20
.16
.13
.11
150
.69
.57
.49
.38
.31
.26
.19
.15
.12
.10
200
1.2
0
1.0
0
.85
.66
.54
.46
.33
.26
.21
.18
.14
.11
250
1.5
3
1.3
1
1.0
2
.83
.70
.51
.40
.33
.28
.21
.17
.15
.13
300
1.8
9
1.4
7
1.2
0
1.0
1
.73
.57
.47
.40
.31
.26
.21
.18
400
2.5
0
2.0
4
1.7
3
1.2
5
.98
.80
.68
.52
.42
.36
.31
500
3.8
7
3.1
6
2.6
7
1.9
3
1.5
1
1.2
4
1.0
5
.81
.65
.55
.48
600
4.5
0
3.8
1
2.7
5
2.1
5
1.7
7
1.5
0
1.0
5
.93
.79
.68
800
4.8
7
3.8
2
3.1
3
2.6
6
2.0
4
1.6
5
1.3
9
1.2
0
1000
7.5
5
5.9
0
4.8
5
4.1
2
3.1
6
2.5
6
2.1
6
1.8
6
1250
9.1
2
7.4
9
6.3
5
4.8
7
3.9
6
3.3
2
2.8
7
1500
10.8
9.1
7
7.0
2
5.7
0
4.8
0
4.1
4
1750
12.5
9.5
4
7.7
4
6.5
0
5.6
2
2000
16.3
12.5
1
0.1
8.5
0
7.3
5
2250
15.8
1
2.8
10.8
9.3
0
2500
19.4
1
5.8
13.3
11.4
2
SCHEDULE
40
NOMINAL
CFM
PIPESIZE
FREEAIR
LINEPRESSURE-PSIG
10
15
20
30
40
50
75
100
125
150
200
25
0
300
350
8/12/2019 CPR Tech Air Brochure
9/161316
Inlettemperature
125
120
115
110
10
5
100
95
90
Inletwatervapor-lbs./
hr.
4.7
168
4.1
008
3.5
552
3.0
756
2.6
53
2
2.2
836
1.9
580
1.6
764
Lbs.waterremo
ved/hr.
4.2
900
3.6
740
3.1
284
2.6
588
2.2
26
4
1.8
565
1.5
312
1.2
496
Waterremoved,
percent
90.9
5
89.5
9
87.9
9
86.1
2
83.9
1
81.3
1
78.2
0
74.5
4
Percentofdesig
npoint
280.2
239.9
204.3
172.9
145.4
121.1
100.0
81.6
Sensibleload-btu./
hr.
3181
2969
2757
2545
233
3
2121
1
908
1697
Latentload-btu
./hr.
4595
3935
3351
2837
242
5
1989
1
640
1338
Totalload-btu./hr.
7676
6894
6108
5382
475
8
4110
3
548
3035
Percentofdesig
n
216.3
194.3
172.2
181.7
134.1
115.8
100
85.5
Operationkw./h
r.
.67
.60
.53
.47
.4
1
.36
.31
.27
Table1.Refrigera
tedAirDryerPerformance(11d
ataper100CFM@
100PSIG)
50FDe
w-PointUnit
35FDe
w-PointUnit
Inlettemperature
125
120
115
110
10
5
100
95
90
Inletwatervapor-lbs./
hr.
4.7
168
4.1
008
3.5
552
3.0
756
2.6
53
2
2.2
836
1.9
580
1.6
764
Lbs.waterremo
ved/hr.
4.4
792
3.8
632
3.3
176
2.8
380
2.4
15
6
2.0
460
1.7
204
1.4
388
Waterremoved,
percent
94.9
6
94.2
0
93.3
1
92.2
7
91.1
0
89.6
0
8
7.0
0
84.8
0
Percentofdesig
npoint
260.4
224.1
5
192.8
164.9
140.4
118.9
100.0
83.6
Sensibleload-btu./
hr.
3818
3605
3393
3181
296
9
2757
2
544
2332
Latentload-btu
./hr.
4797
4134
3545
3042
258
1
2191
1
842
1540
Totalload-btu./hr.
8615
7739
6938
6223
554
0
4948
4
386
3872
Percentofdesig
n
196.4
176.4
159.2
141.9
126.3
112.8
100.0
88.3
Operationkw./h
r.
1.1
0
.99
.89
.78
.7
1
.63
.56
.49
20
.45
.38
.32
.25
.20
.17
.13
.10
35
1.2
9
1.0
7
.92
.71
.58
.49
.35
.28
.23
.19
.15
.12
.10
50
1.8
1
1.4
0
1.1
5
.97
.70
.55
.45
.38
.29
.24
.20
.17
75
3.1
0
2.5
3
2.1
4
1.5
4
1.2
1
.99
.84
.65
.52
.44
.38
100
4.3
9
3.7
0
2.6
8
2.0
9
1.7
2
1.4
6
1.1
2
.91
.76
.66
125
5.7
0
4.1
0
3.2
2
2.6
4
2.2
4
1.7
2
1.3
9
1.1
7
1.0
1
150
5.8
8
4.6
0
3.7
8
3.2
0
2.4
6
1.9
9
1.6
8
1.4
5
200
8.0
5
6.6
1
5.6
1
4.3
0
3.4
9
2.9
4
2.5
3
250
10.3
8.8
7
6.7
2
5.4
5
4.5
9
3.9
6
300
12.6
9.6
6
7.8
5
6.6
0
5.7
0
400
17.2
14.0
11.7
10.1
500
21.8
18.3
15.8
LINEPRESSURE-PSIG
10
15
20
30
40
50
75
100
125
150
200
2
50
300
350
1
SCHEDULE
40
FRICTIONLO
SSOFAIRIN
PIPE-
PRESSURELOSSIN
POUNDSFOREAC
H100FEETOFSTRAIGHTPIPE
CONTINUED
NOMINAL
CFM
PIPESIZE
FREEAIR
8/12/2019 CPR Tech Air Brochure
10/16
DETERMINING ADDITIONAL
COMPRESSED AIR REQUIRED TO
BRING YOUR AIR SYSTEM
BACK TO 100 PSIG
Once the actual existing compressed air capacity is known, it isrelatively easy to mathematically determine the air required to bring the
air system up to 100 PSIG:
CFM P2P1
653 (114.7) = 884 CFM84.7
Therefore, the total air capacity required to hold 100 PSIG is 884 CFMand the additional then is 884 - 653 or 231 cubic feet per minute.Additional compressed air is required tomeetthe current demand.
Depending on the type of system and type of air supply, a leakage orunload factor should be added to any requirement. This is generallyfrom 20% to 30% depending on the condition.
Using a 20% extra capacity factor, the total air requirement would thenbe 884 x 1.20 = 1060 CFM and an additional (1060 - 653) 408 CFMwould be recommended.
ANALYZING THE COST OF
SYSTEM LEAKS
A shortage in capacity is often due to or certainly partially due to systemleakage. Air system leaks are a continuing source of lost power andshould always be minimized. A number of small leaks to that of a 1/4orifice would at 100 PSIG pass CFM of compressed air. This is a25HP air compressor to you. A .04 per KWH operating 8,000 hoursper year, (3 shifts) this would cost you $6,600 in power cost to do nowork.
Defective tools, shut-off valves, packings, fit-ups, drain cocks, etc.,should be continually checked. Most plants can always afford the
maintenance labor and parts to correct leaks. Total system leakagecan be identified by measuring time in seconds for the system (receiver)pressure to drop from 100 to 90 PSIG with no air supply or usage:
For example, assume the total receiver and piping of the system is 120cubic feet. If the plant has a 90 second bleed down rate is 90 PSIGwhen no production air is being used, this is leakage.
The calculated leakage capacity is:
(120) (114.7 - 104.7) (60) = 54 CFM
(90) 14.7
TOTAL COMPRESSED AIR LEAKAGE = 54 CFM X 1.15 = 62 CFM
* Add 15% to adjust for the higher leakage rate at the 120 PSIG to 90PSIG (30 PSIG x .5)
* Any leakage rate beyond 5% of the total system should be corrected.
CFM (REQUIRED) =
CFM (REQUIRED) =
CFM (LEAKAGE) =
2 27
GENERAL TERMS CONTINUED
SINGLE-ACTING COMPRESSORS:Are mach ines which compress on only one side of the piston.Compression takes place on only one stroke per revolution of thecompressing element.
DOUBLE-ACTING COMPRESSORS:Are machines which compress on both sides of the piston. The
running gear consists of a crank and crosshead mechanism with thepiston rod attached to the crosshead, and extending into thecompressor cylinder through a packing box. Compression takes placeon both strokes in each revolution.
AIR RECEIVERS:Are large tanks placed in compressed air systems. A receiver actsprimarily as a pulsation damper and warehouse for air. It also serves tocollect condensate. Consequently, it is advisable to equip receiverswith automatic moisture traps.
SINGLE STAGE COMPRESSORS:
Are machines which use only one step or stage to compress from theinitial pressure to the final discharge pressure.
MULTI-STAGE COMPRESSORS:Are machines which use more than one step or stage to compress fromthe initial pressure to the final discharge pressure. For example, a twostage compressor compresses in two steps; a three stage compressorcompresses in three steps, etc.
INTERCOOLERS:Are heat exchangers used to remove the heat of compression betweenstages of compression on multi-stage compressors.
AFTERCOOLERS:Are heat exchangers designed to remove the heat of compression afterthe final stage of compression in addition to removing moisture fromthe compressed air.
MOISTURE SEPARATORS:Are used generally in conjunction with aftercoolers and intercoolers tocollect and remove the moisture which has condensed in compressedair lines.
AUTOMATIC MOISTURE TRAPS:Are devices designed to automatically eject from the system themoisture collected in the separator.
ABSOLUTE PRESSURE:Is the existing gauge pressure (as read on a gauge) plus atmosphericpressure. Atmospheric pressure at sea level is 14.7 PSIA; therefore,for 100 pounds gauge, the absolute pressure (PSIA) is 100 plus 14.7,or 114.7 PSIA.
RATIO OF COMPRESSION:Is the absolute discharge pressure divided by the absolute suction
pressure. For a compressor taking in atmospheric air at sea level andcompressing it to 100 pounds gauge, the ratio of compression is114.7/114.7 = 7.8.
(Note that in compressors, ratio of compression is a ratio of pressures.It should not be confused with the similar term used by internalcombustion engine manufacturers. In engines, ratio of compression isa ratio of volumes)
8/12/2019 CPR Tech Air Brochure
11/16
HP x .746 x HRS. x RATEMOTOR EFFICIENCY
WHAT IS ELECTRIC ENERGY COST?
ELECTRIC ENERGY COST (DOLLARS) =
This is the formula for electric energy cost in dollars, and you can see itis a function of:
The number of hours of operation
The power used to drive the Compressor (HP) The power rate (cents per kW) The motor efficiency
This formula is acceptable as accurate for estimating and comparisonpurposes. (Your actual power bill can be further affected positively ornegatively by such things as Power Factor - Demand Charges, etc.).
THE MAGNITUDE OF
ENERGY COST (ELECTRIC)!
To see the magnitude of your potential expenditure in power cost,calculate the power cost of a 100 HP Air Compressor:
6,000 hours a year Rate of $.07/kW Motor efficiency .90
(100) (.746) (6,000) (.07).90
ELECTRIC ENERGY COST = $34,800 PER YEAR
A 100 HP Air Compressor would have a $34,800 per year power cost.
The initial purchase price of a 100 HP Air Compressor, lubricated, for
plant air will probably range from $35,000 to $50,000 depending on the
type.
In short, the ELECTRIC ENERGY COST OF OPERATIONin a Heavy
Duty Cycle-Full Load 6,000 Hours (2 Shifts Plus)) CAN EQUAL OR
EXCEED THE INITIAL COST OF THE UNIT EVERY YEAR. Perhaps
we should pay attention to this often overlooked continuing cost. A
POSITIVE VARIANCE OF 15% - 25% in energy cost can be a
significant savings in any operation, and this is obtainable.
CONVERSION FACTORS
4 25
TERMINOLOGY
CFM DISPLACEMENT:
CUBIC FEET PER MINUTE measures the volume displaced by theair compressor at full RPM - but not Delivered Air or Usable Air.
CFM DELIVERED CUBIC FEET PER MINUTE:
Volume of air delivered to the system by the air compressor at ratedpressure.
ICFM:
INLET CFM is rated volume of Inlet air (at Inlet conditions i.e.:temperature and pressure 14.7 PSIG at sea level) taken in to thecompressor.
ACFM:
Is the actual cubic feet per minute of inlet compressed air delivered tothe system at a specified point at the final discharge pressure. i.e.: thecompressor delivers 625 ACFM of compressed air at 100 PSIG at thedischarge end of the aftercooler.
SCFM:
Standard Cubic Feet Per Minute is ACFM or ICFM CONVERTED tostandard intake conditions - (60F, 0% RH & 14.7 PSIG usually) forrating using equipment. To size for other than standard conditions, i.e.:altitude or hot weather corrections must be made.
PSI:
Pounds Per Square Inch - A rating of air pressure in the system.
PSIA ABSOLUTE:Pressure. i.e.: Sea level - 14.7 PSIA or 0 PSIG (gauge pressure).
PSIG:
Gauge pressure shows amount of air pressure above ambient; i.e.:Sea level = 0 PSIG = 14.7 PSIA.
CONSTANT SPEED CONTROL:Unit runs continuously but matches air supply to demand by loadingor unloading the compressor.
FULL LOAD:
Air compressor is running at FULL RPM with Fully Open Inlet andDischarge delivering maximum volume (ACFM) at Rated Pressure(PSM).
FOR EXAMPLE
Inlet = 700 ICFM Co mpressed to 625 ACFMat 14.7 PSIA, 0 PSIG at 114.7 PSIA, 100 PSIG
Kilowatt Hours (kW h) Horsepower Hours (hp h) 1.341 0
Watts (W) Horsepower (hp) 0.001341 0
TO CONVERT FROM TO DIVIDED BY
Bars Pounds Force per Sq. In. (lbf/in2) (PSI) 14.504
ELECTRIC ENERGY COST =
TO CONVERT FROM TO MULTIPLY BY
8/12/2019 CPR Tech Air Brochure
12/16
15
15
15
15
15
15
15
15
20
35
45
60
60
8
0
90
100
110
150
200
200
250
1.8
2.5
3.2
4
5
6.25
10
15
20
25
30
40
50
6
0
80
90
100
150
175
200
300
6 23
AUTOMOTIVE SERVICE
EQUIPMENT
AIR AVG. FREE
PRESSURE EQUIPMENT AIR CONS.
RANGE CFM
70- 100 *Air Filter Cleaner 3.0
70- 100 *Body Polisher 2.070 -100 *Body Sander (Orbital) 5.0
70- 100 *Brake Tester 3.5
70- 100 *Carbon Remover 3.0
70- 100 *Carwasher 8.5
90 -100 Dusting Gun (Blow Gun) 2.5
120-150 *Grease Gun 3.0
70- 100 *Panel Cutter 4.0
70- 90 Drill, 1/16 to 3/8 4.0
125 - 150 *Impact Wrench, 3/8 sq.dr. 2.0
125 - 150 *Impact Wrench, 1/2 sq.dr. 3.5125 - 150 *Impact Wrench, 5/8 sq.dr. 5.0
125 - 150 *Impact Wrench, 3/4 sq.dr. 7.5
125 - 150 *Impact Wrench, 1 sq.dr. 10.0
70- 90 *Die Grinder 5.090 -100 *Vertical Disc Sanders 10.0
90-100 *Fi ling & Sawing Machin e, small 3.0
90-100 *Filing & Sawing Mach ine, large 5.0
90- 100 *Burring Tool 5.0
145- 175 Hydraulic Lift 6.0125-150 Hydraulic Floor Jack 6.0
120 -150 Pneumatic Garage Door 3.0
90- 100 Radiator Tester 1.0
90- 100 Spark Plug Cleaner 5.0
90- 100 Spark Plug Tester 0.5
HAMMERS
90- 100 *Air Hammer 4.0
90- 100 *Tire Hammer 12.0
125-150 *Bead Breaker 12.0
SPRAY GUNS
90- 100 *Engine Cleaner 5.0
90-100 *Pai nt Spray Gu n (P roducti on) 8.5
90 - 100 *Paint Spr ay Gun (Touch-up) 3.5
90-100 *Paint Spray Gun (Undercoating) 19.0
90- 100 Spring Oiler 4.0
TIRE TOOLS
125-150 Rim Stripper 6.0
125-150 Tire Changer 1.0
125-150 Tire Inflation Line 1.5
125-150 Tire Spreader 1.0
125-150 *Vacuum Cleaner 6.5THREEPHAS
EMOTOR
DATA
-F o
r60Hz1800RPMS
tandardMotorCO N
TINUED
MOTOR
1/2
3/4
1
11/2
2
3
5
71/2
10
15
20
25
30
40
50
60
75
100
125
150
200
15
15
15
15
15
15
15
20
25
40
60
70
80
9
0
100
110
125
200
225
250
350
2
3.2
4
5.6
6.25
8
15
20
20
30
40
50
60
8
0
100
100
150
175
200
250
350
MOTOR
SYSTEM
460V
(480V)
MOTOR
SYSTEM
575V
(600V)
1.1
1.6
2.1
3.0
3.4
4.8
7.6
11
14
21
27
34
40
5
2
65
77
96
124
156
180
240
14
14
14
14
14
14
14
14
14
10
10
8
8
6
4
3
1
2/0
3/0
4/0
350
0.9
1.3
1.7
2.4
2.7
3.9
6.1
9.0
11
17
22
27
32
4
1
52
62
77
99
125
144
192
14
14
14
14
14
14
14
14
14
12
10
10
8
6
6
4
3
1
2/0
3/0
250
FULLLOADCURREN
T
(NEC)-AMPSMINIMUM
COPPERWIRESIZE
-
(75C)THW,THHN-
THWN,XHHW-SIZE
CIRCUITBREAKER
Thermal-MagneticBreaker
TripRating-AMPS
FUSIBLESWITCH
WithDualElementTime
DelayFuse-AMPS
FULLLOADCURREN
T
(NEC)-AMPSMINIMUM
COPPERWIRESIZE
-
(75C)THW,THHN-
THWN,XHHW-SIZE
CIRCUITBREAKER
Thermal-MagneticBreaker
TripRating-AMPS
FUSIBLESWITCH
WithDualElementTime
DelayFuse-AMPS
8/12/2019 CPR Tech Air Brochure
13/16
8 21
1/8 115 130 140 165
3/16 (*3) 260 290 320 375
1/4 (*4) 460 500 560 660
5
/16 (*5) 725 825 900 1050
3/8 (*6) 1050 1155 1260 1475
7/16 (*7) 1450 1600 1750 2050
1/2 (*8) 1850 2000 2250 2650
5/8 (*10) 2900 3125 3520 4100
3/4 (*12) 4180 4500 5060 5950
1/8 18 20 22 26
3/16 (*3) 41 45 49 58
1/4 (*4) 72 80 90 105
5/16 (*5) 113 125 140 160
3/8 (*6) 163 182 200 235
7/16 (*7) 215 240 270 315
1/2 (*8) 290 320 350 410
5/8 (*10) 454 500 550 640
3/4 (*12) 652 720 790 925
BLASTING DATA
APPROXIMATE AIR CONSUMPTION(CFM) PER BLAST NOZZLE
NOZZLE
SIZE
NOZZLE PRESSURE
80 PSI 90 PSI 100 PSI 120 PSI
NOZZLE
SIZE
NOZZLE PRESSURE
80 PSI 90 PSI 100 PSI 120 PSI
APPROXIMATE ABRASIVECONSUMPTION (LBS./HR.)
PER BLAST NOZZLE
Air volume and pressure are very important. The blasting production
rate will increase with higher blasting pressures and decrease with lower
blasting pressures. The National Association of Corrosion Engineers
data suggests that 1.5% of production is lost for each 1 PSI reduction in
blast nozzle pressure. Pressure drop through the blast unit itself is
normally less than 1 PSI. Air pressure loss can be avoided by using the
shortest possible hose of adequate size. SINGLEPHASEMOTOR
DATA
(60Hz)
MOTOR
SYSTEM
115V
(120V)
MOTOR
1/6
1/
4
1/3
1/2
3/
4
1
11/2
2
3
5
71/2
10
MOTOR
SYSTEM
230V
(240V)
15
15
15
20
25
30
40
5
0
70
90
11
0
--
6.25
9
10
15
20
25
30
3
0
50
80
10
0
--
FULLLOADCURRE
NT(NEC)-
AMPSMINIMUMC
OPPERWIRE
SIZE-(75C)THW,
THHN-THWN,
XHHW-SIZE
CIRCUITBREAKER
Thermal-MagneticB
reakerTrip
Rating-AMPS
FUSIBLESWITCH
WithDualElementTimeDelay
Fuse-AMPS
FULLLOADCURRE
NT(NEC)-
AMPSMINIMUMC
OPPERWIRE
SIZE-(75C)THW,THHN-THWN,
XHHW-SIZE
CIRCUITBREAKER
Thermal-MagneticBreakerTrip
Rating-AMPS
FUSIBLESWITCH
WithDualElementTimeDelay
Fuse-AMPS
2.2
2.
9
3.6
4.9
6.9
8
10
1
2
17
28
4
0
50
14
14
14
14
14
14
14
14
12
10
8
6
15
15
15
15
15
15
20
25
35
60
8
0
90
3.2
4.
5
5.6
7
10
12
15
2
0
25
40
6
0
60
4.4
5.
8
7.2
9.8
13
.8
16
20
24
34
56
8
0
--
14
14
14
14
14
14
12
10
8
4
3
--
LOSS OF AIR PRESSURE
8/12/2019 CPR Tech Air Brochure
14/16
10 19
LOSS OF AIR PRESSUREDUE TO FRICTION - IN PSI 100 FT.OF PIPE OR HOSE 100 PSI GAUGE
INITIAL PRESSURE
For longer or shorter lengths of pipe or hose, the friction loss isproportional to the length; i.e.: for 50 ft., one-half of the above; for 400 ft.,four times the above, etc.
NOTES:
1. These figures are for estimating - different types of pipe and hosemay have rougher linings and cause higher pressure drops.
2. Couplings and fittings increase the pressure drop some.
3. Lower initial pressures cause increased pressure drop.
4. Higher initial pressure causes lower pressure drop.
Piping for a sample system of 3,000 CFM at 100 PSIG of central air, withfive 600 CFM uses figured according to the chart for loss of air pressuredue to friction.
CU. FT. EQUIVALENTFREE CU. FT.AIR COMPRESSED
PER MIN. AIR/MIN.
TYPICALNominal Diameter, In. (I.D.)
1/2 3/4 1 11/4 11/2 2 21/2 3 31/2 4
10 1.28 2.6 .1 .03
20 2.56 6.9 .4 .11 .03 .01
30 3.84 .59 .9 .25 .06 .07
40 5.12 1.6 .45 .10 .05
50 6.41 2.5 .69 .16 .07 .02
60 7.68 3.6 1.00 .23 .10 .03
70 8.96 4.9 1.40 .32 .14 .04
80 10.24 6.5 1.80 .41 .18 .05 .02
90 11.52 8.3 2.30 .52 .23 .06 .02
100 12.81 2.80 .65 .29 .08 .03125 15.82 4.90 1.0 .45 .12 .05
150 19.23 6.30 1.5 .64 .17 .07 .02
175 22.40 1.9 .87 .24 .09 .03
200 25.62 2.6 1.14 .31 .12 .04 .02
250 31.64 4.0 1.79 .49 .19 .06 .03
300 38.44 5.8 2.58 .69 .27 .08 .04 .02
350 44.80 3.51 .94 .36 .11 .05 .03
400 51.24 4.58 1.21 .48 .15 .07 .04
450 57.65 5.80 1.54 .59 .19 .09 .05500 63.28 7.16 1.92 .74 .23 .11 .06
600 76.88 2.76 1.07 .34 .16 .08
700 89.60 3.77 1.45 .46 .21 .11
800 102.50 4.90 1.90 .59 .28 .14
900 115.30 6.23 2.41 .76 .35 .18
1000 128.10 7.69 2.98 .93 .44 .22
1500 192.30 6.70 2.10 .98 .49
2000 256.20 3.74 1.73 .88
2500 316.40 5.84 2.72 1.38
3000 384.60 8.41 3.91 2.003500 447.80 5.82 2.72
4000 512.40 6.94 3.55
FRICTION
LO
SSOFAIRIN
PIPE
-PRESSURELOSSI
N
POUNDSFOREAC
H
100FEETOFSTRAIGHTPIPE
CONTINUED
150
.29
.24
.22
.16
.13
.11
200
.50
.42
.36
.28
.23
.19
.14
.11
250
.80
.64
.55
.43
.35
.29
.21
.17
.14
.12
300
1.0
8
.90
.77
.60
.49
.41
.30
.23
.19
.16
.13
.10
400
1.5
7
1.3
4
1.0
4
.85
.72
.52
.41
.33
.28
.22
.18
.15
.13
500
2.0
7
1.6
0
1.3
1
1.1
1
.80
.63
.51
.44
.33
.27
.23
.20
600
2.9
5
2.2
8
1.8
7
1.5
8
1.1
4
.89
.73
.62
.48
.39
.33
.28
800
4.0
0
3.2
7
2.7
6
2.0
0
1.5
6
1.2
8
1.0
9
.83
.68
.57
.49
1000
5.1
7
4.3
0
3.1
0
2.4
3
1.9
9
1.6
9
1.3
0
1.0
5
.88
.76
1250
6.7
8
4.8
9
3.8
3
3.1
4
2.6
6
2.0
4
1.6
6
1.3
9
1.2
0
1500
6.8
5
5.3
6
4.4
0
3.7
3
2.8
7
2.3
2
1.9
5
1.6
8
2000
9.4
0
7.8
2
6.5
5
5.0
2
4.0
7
3.4
2
2.9
6
2500
12.1
10.3
7.8
6
6.3
9
5.3
6
4.6
2
3000
14.7
11.3
9.1
3
7.7
0
6.6
2
3500
15.4
1
2.5
10.5
9.0
2
4000
20.0
1
6.3
13.7
11.8
21/2
SCHEDULE
40
NOMINAL
CFM
PIPESIZE
FREEAIR
LINEPRESSURE-PSIG
10
15
20
30
40
50
75
100
125
150
200
250
300
350
8/12/2019 CPR Tech Air Brochure
15/16
12 17
LINEPRESSURE-PSI
G
10
15
20
30
40
50
75
100
125
150
200
2
50
300
350
50
.31
.25
.22
.17
.14
.12
75
.65
.54
.46
.36
.29
.25
.18
.14
.12
.10
100
1.1
3
.94
.80
.62
.51
.43
.31
.24
.20
.17
.13
.11
125
1.4
4
1.2
4
.96
.78
.66
.48
.37
.31
.26
.20
.16
.14
.12
150
2.0
4
1.7
5
1.3
5
1.1
1
.94
.68
.53
.43
.37
.28
.23
.19
.17
200
3.0
4
2.3
6
1.9
3
1.6
3
1.1
8
.92
.76
.64
.49
.40
.34
.29
250
3.6
8
3.0
1
2.5
4
1.8
3
1.4
4
1.1
8
1.0
0
.77
.62
.52
.45
300
4.2
9
3.6
2
2.6
2
2.0
5
1.7
4
1.4
3
1.0
9
.89
.75
.64
400
6.3
5
4.5
8
3.5
9
2.9
4
2.5
0
1.9
2
1.5
5
1.3
1
1.1
3
500
7.1
2
5.5
9
4.5
9
3.8
9
2.9
8
2.4
2
2.0
3
1.7
6
600
8.0
0
6.5
5
5.5
5
4.2
6
3.4
6
2.9
1
2.5
1
700
10.8
8.8
9
7.5
5
5.7
8
4.7
0
3.9
5
3.4
0
800
11.6
9.8
0
7.5
0
6.1
0
5.1
2
4.4
2
1000
15.2
11.7
9.4
5
7.9
5
6.8
6
1200
16.4
1
3.3
11.2
9.6
1
1400
22.9
1
8.6
15.6
13.5
11/2
SCHEDULE
40
NOMINAL
CFM
PIPESIZE
FREEAIR
FRICTIONLO
SSOFAIRIN
PIPE
-PRESSURELOSSIN
POUNDSFOREACH100FEETOFSTRAIGHTPIPE
CONTINUED
FRICTIONOF
AIRIN
HOSE-
Pulsa
ting
Flow
*CONTI
NUED
50
--
--
0.1
0.2
0.2
0.3
0.4
0.5
0.7
1.1
60
--
--
--
0.1
0.2
0.3
0.3
0.5
0.6
0.8
1.0
1.2
1.5
70
--
--
--
0.1
0.2
0.2
0.3
0.4
0.4
0.5
0.7
0.8
1.0
1.3
80
--
--
--
--
0.1
0.2
0.2
0.3
0.4
0.5
0.6
0.7
0.8
1.0
90
--
--
--
--
0.1
0.2
0.2
0.3
0.3
0.4
0.5
0.6
0.7
0.8
100
--
--
--
--
--
0.1
0.2
0.2
0.3
0.4
0.4
0.5
0.6
0.7
110
--
--
--
--
--
0.1
0.2
0.2
0.3
0.3
0.4
0.5
0.5
0.6
50
--
--
--
--
--
0.1
0.2
0.2
0.2
0.3
0.3
0.4
0.5
0.6
60
--
--
--
--
--
--
0.1
0.2
0.2
0.2
0.3
0.3
0.4
0.5
70
--
--
--
--
--
--
--
0.1
0.2
0.2
0.2
0.3
0.3
0.4
80
--
--
--
--
--
--
--
--
0.1
0.2
0.2
0.2
0.3
0.4
90
--
--
--
--
--
--
--
--
--
0.1
0.2
0.2
0.2
0.3
100
--
--
--
--
--
--
--
--
--
--
0.1
0.2
0.2
0.2
110
--
--
--
--
--
--
--
--
--
--
0.1
0.2
0.2
0.2
11/4
11/2
CU.F
T.FREEAIRP
ERMIN.
PASSINGTHROUGH
50FT.LENGTHSOFHOSE
20
30
40
50
60
70
80
90
100
110
120
130
140
150
LOSSOF
PRESSURE(PSI)IN50FT.LE
NGTHSOFHOSE
SIZEOFHOSE,
GAUGE
COUPLED
PRESSURE
EACHEND,IN.
ATLINE,LB.
*Forlongerorshorterlengthsofhose,
thefriction
lossisproportionaltothelength,
i.e.:
for25ft.
one-halfoft
heabove;for150ft.,
threetim
estheabove,
etc.
DECIMAL AND METRIC
8/12/2019 CPR Tech Air Brochure
16/16
14 15
DECIMAL AND METRICEQUIVALENTS OF COMMON
FRACTIONS OF AN INCH
FRACTION DECIMAL Mm
FRICTIONLO
SSOFAIRIN
PIPE
-PRESSURELOSSIN
POUNDSFOREACH100FEETOFSTRAIGHTPIPE
LINEPRESSURE-PSI
G
10
15
20
30
40
50
75
100
125
150
200
2
50
300
350
10
1.45
1.2
4
.96
.79
.67
.48
.38
.31
.26
.20
.16
.14
.12
15
2.6
8
2.0
8
1.7
0
1.4
3
1.0
4
.81
.67
.57
.43
.35
.30
.25
20
3.6
0
2.9
4
2.4
8
1.8
0
1.4
1
1.1
5
.98
.75
.61
.51
.44
30
5.4
0
3.9
0
3.0
5
2.5
0
2.1
2
1.6
3
1.3
2
1.1
1
.96
40
6.8
0
5.3
1
4.3
7
3.7
0
2.8
4
2.3
0
1.9
4
1.6
7
50
8.2
0
6.7
5
5.7
0
4.3
7
3.5
5
2.9
9
2.5
8
60
11.7
9.6
1
8.1
6
6.2
5
5.0
8
4.2
7
3.6
8
80
14.4
11.0
8.9
5
7.5
2
6.5
0
100
17.1
1
3.9
11.7
10.1
10
.42
.35
.30
.23
.19
.16
.12
.34
.28
.24
.18
.15
.12
.11
20
1.5
7
1.31
1.1
2
.87
.71
.60
.43
.98
.80
.68
.52
.42
.35
.31
35
3.2
2
2.5
0
2.0
4
1.7
2
1.2
5
1.9
3
1.5
9
1.3
5
1.0
3
.84
.71
.61
50
4.9
5
4.0
5
3.4
2
2.4
7
65
5.7
1
4.1
2
3.2
3
2.6
5
2.2
5
1.7
2
1.4
0
1.1
8
1.0
1
80
6.1
9
4.7
4
3.9
8
3.3
7
2.5
8
2.1
0
1.7
6
1.5
2
100
9.6
0
7.5
3
6.4
0
5.2
5
4.0
2
3.2
6
2.7
4
2.3
7
125
11.7
9.7
0
8.1
2
6.2
2
5.0
5
4.2
5
3.6
7
150
12.6
11.5
8.8
5
7.1
6
6.0
3
5.2
0
200
15.6
1
2.6
10.6
9.1
4
250
1
9.7
16.6
14.3
NOMINAL
CFM
PIPESIZE
FREEAIR
1/2
SCHEDULE
40
3/4
SCHEDULE
40
1/64 0.01562 0.3971/32 0.03125 0.794
3/64 0.04688 1.191
1/16 0.06250 1.5885/64 0.07812 1.984
3/32 0.09375 2.3817/64 0.10938 2.778
1/8 0.12500 3.1759/64 0.14062 3.572
5/32 0.15625 3.96911/64 0.17188 4.366
3/16 0.18750 4.76313/64 0.20312 5.159
7/32 0.21875 5.55615/64 0.23438 5.953
1/4 0.25000 6.350
17/64 0.26562 6.7479/32 0.28125 7.144
19/64 0.29688 7.5415/16 0.31250 7.938
21/64 0.32812 8.33411/32 0.34375 8.731
23/64 0.35938 9.1283/8 0.37500 9.525
25/64 0.39062 9.92213/32 0.40625 10.319
27/64 0.42188 10.7167/16 0.43750 11.113
29/64 0.45312 11.509
15/32 0.46875 11.90631/64 0.48438 12.3031/2 0.50000 12.700
33/64 0.51562 13.09717/32 0.53125 13.494
35/64 0.54688 13.8919/16 0.56250 14.288
37/64 0.57812 14.68419/32 0.59375 15.081
39/64 0.60938 15.4785/8 0.62500 15.875
41/64 0.64062 16.27221/32 0.65625 16.669
43/64 0.67188 17.06611/16 0.68750 17.46345/64 0.70312 17.859
23/32 0.71875 18.25647/64 0.73438 18.653
3/4 0.75000 19.05049/64 0.76562 19.447
25/32 0.78125 19.84451/64 0.79688 20.241
13/16 0.81250 20.63853/64 0.82812 21.034
27/32 0.84375 21.43155/64 0.85938 21.828
7/8 0.87500 22.22557/64 0.89062 22.62229/32 0.90625 23.019
59/64 0.92188 23.41615/16 0.93750 23.813
61/64 0.95312 24.20931/32 0.96875 24.606
63/64 0.98438 25.0031/1 1.00000 25.400