Reznor CAUA Unit Installation Manual - Manual (Page 7)

Form I-CAUA, P/N 164771 R8, Page 7
TABLE 4 -
Sizing a Gas
Supply Line
Capacity of Piping - Cubic Feet per Hour based on 0.3" w.c. Pressure Drop
Specific Gravity for Natural Gas -- 0.6 (Natural Gas -- 1000 BTU/Cubic Ft)
Specific Gravity for Propane Gas -- 1.6 (Propane Gas -- 2550 BTU/Cubic Ft)
Length Diameter of Pipe
of 1/2" 3/4" 1" 1-1/4" 1-1/2" 2"
Pipe Natural Propane Natural Propane Natural Propane Natural Propane Natural Propane Natural Propane
20' 92 56 190 116 350 214 730 445 1100 671 2100 1281
30' 73 45 152 93 285 174 590 360 890 543 1650 1007
40' 63 38 130 79 245 149 500 305 760 464 1450 885
50' 56 34 115 70 215 131 440 268 670 409 1270 775
60' 50 31 105 64 195 119 400 244 610 372 1105 674
70' 46 28 96 59 180 110 370 226 560 342 1050 641
80' 43 26 90 55 170 104 350 214 530 323 990 604
90' 40 24 84 51 160 98 320 195 490 299 930 567
100' 38 23 79 48 150 92 305 186 460 281 870 531
125' 34 21 72 44 130 79 275 168 410 250 780 476
150' 31 19 64 39 120 73 250 153 380 232 710 433
175' 28 17 59 36 110 67 225 137 350 214 650 397
200' 26 16 55 34 100 61 210 128 320 195 610 372
Note: When sizing supply lines, consider possibilities of future expansion and increased requirements.
Refer to National Fuel Gas Code for additional information on line sizing.
Gas Piping
Requirements and
Connection
Pipe joint compounds (pipe dope) shall be resistant to the action of liquefied
petroleum gas or any other chemical constituents of the gas being supplied.
Install a ground joint union and manual shutoff valve upstream of the unit control
system as shown in FIGURE 2. The 1/8" plugged tapping in the shutoff valve pro-
vides connection for a supply line pressure test gauge. The National Fuel Gas Code
requires the installation of a trap with a minimum 3" (76mm) drip leg. Local codes may
require a minimum drip leg longer than 3", typically 6" (152mm). Bleed gas lines of
trapped air.
Gas connection is either 1/2" or 3/4" depending on size and type of gas (See TABLE
5).
Leak-test all connections by brushing on a leak-detecting solution.
TABLE 5 - Gas
Connection (not supply
line size)
FIGURE 2 - Supply
Piping Connection
WARNING
All components of a gas supply system must be leak tested prior to placing equipment in service.
NEVER TEST FOR LEAKS WITH AN OPEN FLAME. Failure to comply could result in personal injury,
property damage or death.
CAUA
Sizes
Fuel
Gas
Connection
150-
200 Natural
Gas
1/2"
250-
400
3/4"
150-
400 Propane
1/2"
From Gas Supply
(horizontal or vertical)
Manual shutoff
Pipe nipple extending
outside the cabinet.
Drip
Leg
To Gas Valve
(inside the
cabinet)
To Gas Valve
(inside the
cabinet)
Ground
Joint
Union
Drip
Leg
Ground Joint Union
Manual shutoff
Gas Valve The main operating gas valve is powered by the 24-volt control circuit through the
thermostat and safety controls. The main control valve is of the diaphragm type pro-
viding regulated gas flow preset at the factory.
WARNING:
The operating valve is the prime safety shutoff. All gas supply lines must be free of dirt or scale
before connecting the unit to ensure positive closure. See Hazard Levels, page 2.