Reznor RDF Unit Installation Manual - Manual (Page 9)

I-RDF, PN148384R5, Page 9
6.1 Gas Piping and Pressures
All piping must be in accordance with the requirements of the National Fuel Gas Code
ANSI/Z223.1 (latest edition) or CSA B149.1 and B149.2. Gas supply piping installa-
tion must conform with good practice and with all local codes. Read this section of the
installation manual to determine the minimum gas supply pressure required to provide
a maximum gas capacity. Minimum gas supply pressure is also stated on the heater
rating plate. The heater manifold terminates at the gas supply connection with a black
iron pipe union. See FIGURE 7. Local codes may require a 6" condensate trap. Gas
connection is either 1", 1-1/4", or 2" depending on the size of the system.
WARNING: High pressure testing of supply lines is acceptable, provided the supply
line has been disconnected from the unit and the pipe end is capped. See Hazard
Levels, page 2.
FIGURE 7 - Gas
Supply Connection
6.0 Mechanical
From Gas Supply
(horizontal or vertical)
Manual
shutoff
Drip
Leg
*To Gas
Valve
(inside the
cabinet)
*To Gas
Valve
(inside the
cabinet) Ground
Joint
Union
Drip
Leg
Ground Joint Union
Manual shutoff
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
of Pipe
Diameter of Pipe
1" 1-1/4" 1-1/2" 2" 2-1/2" 3" 4"
Natural Propane Natural Propane Natural Propane Natural Propane Natural Propane Natural Propane Natural Propane
20' 350 214 730 445 1100 671 2100 1281 3300 2013 5900 3599 12000 7320
30' 285 174 590 360 890 543 1650 1007 2700 1647 4700 2867 9700 5917
40' 245 149 500 305 760 464 1450 885 2300 1403 4100 2501 8300 5063
50' 215 131 440 268 670 409 1270 775 2000 1220 3600 2196 7400 4514
60' 195 119 400 244 610 372 1105 674 1850 1129 3250 1983 6800 4148
70' 180 110 370 226 560 342 1050 641 1700 1037 3000 1830 6200 3782
80' 170 104 350 214 530 323 990 604 1600 976 2800 1708 5800 3538
90' 160 98 320 195 490 299 930 567 1500 915 2600 1586 5400 3294
100' 150 92 305 186 460 281 870 531 1400 854 2500 1525 5100 3111
125' 130 79 275 168 410 250 780 476 1250 763 2200 1342 4500 2745
150' 120 73 250 153 380 232 710 433 1130 689 2000 1220 4100 2501
175' 110 67 225 137 350 214 650 397 1050 641 1850 1129 3800 2318
200' 100 61 210 128 320 195 610 372 980 598 1700 1037 3500 2135
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 Supply Piping
Supply Pressure
Requirement by
Manifold Option
These direct-fired makeup air systems are designed to operate on a natural gas sup-
ply differential pressure range of a minimum of 4.3-5.0" w.c. plus the manifold pres-
sure drop. Maximum supply pressure depends on specific unit firing rate and manifold
selection. If the natural gas supply pressure is above the maximum allowed, it is nec-
essary to install a field-supplied step-down gas regulator in the supply line. Order and
install the appropriate Gas Regulator Kit, Option CZ1 (1") or CZ2 (1-1/2"). These kits
include spring-loaded, lockup type regulators that comply with national and local codes
specifying that type of regulator. Follow the instructions provided with the kit. Measure
the gas pressure between the step-down regulator and the unit.
WARNING: All components of the gas supply system must be leak tested prior to
placing equipment in service. NEVER TEST FOR LEAKS WITH AN OPEN FLAME.
Maximum Supply Pressure by Manifold
Manifold Option BM75, BM76, BM77 - 1/2 psi
Manifold Option BM78, BM79 - 2 psi
Manifold Option BM80, BM81 - 5 psi