Milton CAT G200LG4 200kW_250kVA LG Installation Guide - Manual (Page 12)

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‹ TABLE 2 — GAS FLOW-PIPE SIZE CHART
This table is based on a specific gravity of 1.00 (specific gravity of air). For that reason, a correction is required
when the fuel used has a different specific gravity. The fuel’s specific gravity can be obtained from the fuel supplier.
The table is also based on a pressure drop of 0.3, which allows for a nominal amount of restrictions from bends,
fittings, etc. An example of how to calculate pipe size follows the table.
Example: It is determined that a generator set running at 100% of rated load on natural gas requires 545 cubic
feet of gas per hour. The unit is located 75 feet from the supply tank and will use gas having a specific gravity of
0.65 (multiplier is 0.962). From the table below, it is apparent that a 1-1/2 inch pipe will deliver 524.29 cubic feet
of gas per hour. The next larger pipe (2 inch) will deliver 1120 cubic feet per hour and, when the correction factor
is applied, will actually deliver 1077.4 cubic feet per hour. The 2 inch pipe is required at the given distance of 75
feet. Pressure drop does not have to be considered unless an unusual number of fittings, bends or other restric-
tions are used. In such unusual cases, the fuel supplier will usually specify which multiplier is applicable.
CORRECTION FACTORS
Specific Specific Pressure
Gravity Multiplier Gravity Multiplier Drop Multiplier
0.50 1.10 1.0 0.775 0.1 0.577
0.55 1.04 1.2 0.707 0.2 0.815
(Sewage Gas)
0.60 1.00 1.4 0.655 0.3 1.000
0.65 0.962 1.5 0.633 0.5 1.29
(Natural Gas) (Propane)
0.70 0.926 1.7 0.594 1.0 1.83
0.80 0.867 1.9 0.565 2.0 2.58
0.90 0.817 2.1 0.535 5.0 4.08
(Butane)
Length of Pipe Iron Pipe Size (IPS Inches)
(In Feet) 1/2” 3/4” 1” 1-1/4” 1-1/2” 2” 2-1/2” 3” 4” 6” 8”
15 76 172 345 750 1220 2480 3850 6500 13880 38700 79000
30 52 120 241 535 850 1780 2750 4700 9700 27370 55850
45 43 99 199 435 700 1475 2300 3900 7900 23350 45600
60 38 86 173 380 610 1290 2000 3450 6800 19330 39500
75 77 155 345 545 1120 1750 3000 6000 17310 35300
90 70 141 310 490 1000 1560 2700 5500 15800 32250
105 65 131 285 450 920 1430 2450 5100 14620 29850
120 120 270 420 860 1340 2300 4800 13680 27920
150 109 242 380 780 1220 2090 4350 12240 25000
180 100 225 350 720 1120 1950 4000 11160 22800
210 92 205 320 660 1030 1780 3700 10330 21100
240 190 300 620 970 1680 3490 9600 19740
270 178 285 580 910 1580 3250 9000 18610
300 170 270 545 860 1490 3000 8500 17660
450 140 226 450 710 1230 2500 7000 14420
600 119 192 390 600 1030 2130 6000 12480
Section 1 - General Information
Liquid-cooled Generators