Carrier Infinity 480CEN024 Installation Instruction page 11

Table 2 --Maximum
G as Flow Capacity*
NOMINAL INTERNAL
iRON PiPE DIAMETER LENGTH OF PiPE (FT)t
SIZE (iN.) (iN.)
10 20 30 40 50 60 70 80 90 100 125 150 175 200
1/2 .622 175 120 97 82 73 66 61 57 53 50 44 40
3/4 .824 360 250 200 170 151 138 125 118 110 103 93 84 77 72
1 1.049 680 465 375 320 285 260 240 220 205 195 175 160 145 135
1-1/4 1.380 1400 950 770 600 580 530 490 460 430 400 360 325 300 280
1-1/2 1.610 2100 1460 1180 990 900 810 750 690 650 620 550 500 460 430
Capacity of pipe in eu fl of gas per hr for gas pressure of 0.5 psig or less. Pressure drop of 0.5 in. wg (based oll a 0.60 specific gravity gas). Refer to Table. National Fire Protec
tion Association NFPA 54.
This length includes an ordinary number of fittings.
Step 8--Install Gas Piping
The gas supply pipe enters the unit through the access hole
provided. The gas connection to the unit is made to the 1/2-in. FPT
gas inlet on the gas valve.
Install a gas supply line that runs to the heating section. Refer to
Table 2 and the NFGC for gas pipe sizing. Do not use cast-iron pipe.
It is recommended that a black iron pipe is used. Check the local
utility for recommendations concerning existing lines. Size gas
supply piping for 0.5 in. wg maximum pressure drop. Never use
pipe smaller than the 1/2-in. FPT gas inlet on the unit gas valve.
For natural gas applications, the gas pressure at unit gas connection
nmst not be less than 4.0 in. wg or greater than 13 in. wg while the
unit is operating. For propane applications, the gas pressure nmst
not be less than 7.0 in. wg or greater than 13 in. wg at the unit
connection.
A 1/8-in. NPT plugged tapping, accessible for test gauge
connection, must be installed immediately upstream of the gas
supply connection to the gas valve.
When installing the gas supply line, observe local codes pertaining
to gas pipe installations. Refer to the NFGC ANSI Z223.1-2005
NFPA latest edition (in Canada, CAN/CGA B 149.1). In the absence
of local building codes, adhere to the following pertinent
recommendations:
1. Avoid low spots in long runs of pipe. Grade all pipe 1/4 in.
for every 15 ft of length to prevent traps. Grade all horizontal
runs downward to risers. Use risers to connect to heating
section and to meter.
2. Protect all segments of piping system against physical and
thermal damage. Support all piping with appropriate straps,
hangers, etc. Use a minimum of one hanger eve_ 6 ft. For
pipe sizes larger than 1/2 in., follow recommendations of
national codes.
3. Apply joint compound (pipe dope) sparingly and only to
male threads of joint when making pipe connections. Use
only pipe dope that is resistant to action of liquefied
petroleum gases as specified by local and/or national codes.
Never use Teflon tape.
4. Install sediment trap in riser leading to heating section (See
Fig. 10). This drip leg functions as a trap for dirt and
condensate.
5. Install an accessible, external, manual main shutoff valve in
gas supply pipe within 6 ft of heating section.
6. Install ground-joint union close to heating section between
unit manual shutoff and external manual main shut-off
valve.
7. Pressure test all gas piping in accordance with local and
national plumbing and gas codes before connecting piping
to unit.
IN
TEE
Fig. 10 - Sediment Trap
C99020
NOTE: Pressure test the gas supply system after the gas supply
piping is connected to the gas valve. The supply piping must be
disconnected from the gas valve during the testing of the piping
systems when test pressure is in excess of 0.5 psig. Pressure test the
gas supply piping system at pressures equal to or less than 0.5 psig.
The unit heating section must be isolated from the gas piping system
by closing the external main manual shutoff valve and slightly
opening the ground-joint union.
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in fire, explosion,
personal injury, death and/or property damage.
-Connect gas pipe to unit using a backup wrench to avoid
damaging gas controls.
-Never purge a gas line into a combustion chamber. Never test
for gas leaks with an open flame. Use a commercially available
soap solution made specifically for the detection of leaks to
check all connections.
-Use proper length of pipe to avoid stress on gas control
manifold.
-If a flexible connector is required or allowed by authority
having jurisdiction, black iron pipe shall be installed at furnace
gas valve and extend a minimunr of 2 in. outside furnace casing.
-If codes allow a flexible connector, always use a new
connector, do not use a connector which has previously
serviced another gas appliance.
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