Carrier WeatherExpert 48LC 07 Series Installation Instructions Manual page 14

BRASS FITTING
EMBOSSMENT
FOR 3-6 TON UNITS
Fig. 18 — Gas Line Piping for 6 Ton Units
Other hardware required to complete the installation of the gas
supply line will include a manual shutoff valve, a sediment trap
(drip leg) and a ground-joint union. A pressure regulator valve
may also be required (to convert gas pressure from pounds to
inches of pressure). The manual shutoff valve must be located
within 6 ft (1.83 m) of the unit. The union, located in the final
leg entering the unit, must be located at least 9-in. (230 mm)
away from the access panel to permit the panel to be removed
for service. If a regulator valve is installed, it must be located a
minimum of 4 ft (1220 mm) away from the unit's flue outlet.
Some municipal codes require that the manual shutoff valve be
located upstream of the sediment trap. See Fig. 19 and 20 for
typical piping arrangements for gas piping that has been routed
through the sidewall of the curb. See Fig. 21 for typical piping
arrangement when thru-base is used. Ensure that all piping
does not block access to the unit's main control box or limit the
required working space in front of the control box.
THRU-CURB ADAPTER
SHUT OFF
VALVE
DRIP
LEG
Fig. 19 — Gas Piping with Direct Drip Leg
SUPPORT
BRACKET
9" (229mm) MIN
UNION
UNIT BASE RAIL
BURNER
ACCESS
PANEL
THRU-CURB ADAPTER
SHUT OFF
Fig. 20 — Gas Piping with Offset Drip Leg
Fig. 21 — Gas Piping Thru-Base Connections
When installing the gas supply line, observe local codes per-
taining to gas pipe installations. Refer to the NFPA 54/ANSI
Z223.1 NFGC latest edition (in Canada, CAN/CSA B149.1).
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
in every 15 ft (7 mm in every 5 m) to prevent traps. Grade
all horizontal runs downward to risers. Use risers to con-
nect 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 every
6 ft (1.8 m). For pipe sizes larger than
ommendations 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 petro-
leum gases as specified by local and/or national codes. If
using PTFE (Teflon
Density type and is labeled for use on gas lines. Apply
tape per manufacturer's instructions.
4. Pressure-test all gas piping in accordance with local and
national plumbing and gas codes before connecting piping
to unit.
NOTE: Pressure test the gas supply system after the gas supply
piping is connected to the gas valve. The supply piping must be
1. Teflon is a registered trademark of DuPont.
14
9" (229 mm) MIN
UNION
UNIT BASE RAIL
DRIP
LEG
VALVE
1 / -in., follow rec-
2
1 ) tape, ensure the material is Double
1 / -in.
4