Daikin DBG Series Installation Instructions Manual page 14

Natural Gas Connection
Natural Gas Capacity of Pipe
in Cubic Feet of Gas Per Hour (CFH)
Length of
Pipe in Feet
1/2
10 132
20 92
30 73
40 63
50 56
60 50
70 46
80 43
90 40
100 38
Pressure= .50 PSIG or less and Pressure Drop of 0.3" W.C.
(Based on 0.60 Specific Gravity Gas)
CFH =
Heating Value of Gas (BTU/Cubic Foot
Refer to the Proper Piping Practice drawing for the general
layout at the unit. The following rules apply:
1. Use black iron pipe and fittings for the supply piping.
The use of a flex connector and/or copper piping is
permitted as long as it is in agreement with local
codes.
2. Use pipe joint compound on male threads only. Pipe
joint compound must be resistant to the action of the
fuel used.
3. Use ground joint unions.
4. Install a drip leg to trap dirt and moisture before it can
enter the gas valve. The drip leg must be a minimum
of three inches long.
5. Use two pipe wrenches when making connection to
the gas valve to keep it from turning.
6. Install a manual shut-off valve in a convenient location
(within six feet of unit) between the meter and the unit.
7. Tighten all joints securely.
8. The unit must be connected to the building piping by
one of the following methods:
• Rigid metallic pipe and fittings
• Semirigid metallic tubing and metallic fittings
(Aluminum alloy tubing must not be used in
exterior locations).
• Listed gas appliance connectors used in
accordance with the terms of their listing
that are completely in the same room as the
equipment. Always use a new listed connector.
• In the prior two methods above the connector
or tubing must be protected from physical
and thermal damage. Aluminum alloy tubing
and connectors must be coated to protect
against external corrosion when in contact with
masonry, plaster or insulation or are subject to
repeated wettings by liquids (water - not rain
water, detergents or sewage).
Nominal Black Pipe Size (inches)
3/4 1 1 1/4
278 520 1050
190 350 730
152 285 590
130 245 500
115 215 440
105 195 400
96 180 370
90 170 350
84 160 320
79 150 305
BTUH Furnace Input
1 1 /2
1600
1100
980
760
670
610
560
530
490
460
NOTE: The unit gas supply entrance is factory
sealed with plugs. Keep plugs in place until
gas supply is ready to be installed. Once ready,
replace the plugs with the supplied grommets and
install gas supply line.
Gas Piping Checks
To prevent property damage or personal injury
due to fire, the following instructions must
be preformed regarding gas connections and
pressure testing:
• The unit and its gas connections must be
leak tested before placing in operation.
Because of the danger of explosion or fire,
never use a match or open flame to test for
leaks. Never exceed specified pressures for
testing. Higher pressure may damage gas
valve and cause overfiring which may result
in premature heat exchange failure.
• This unit and its shut-off valve must be
disconnected from the gas supply during
any pressure testing of that system at test
pressures in excess of ½ PSIG (3.48 kPa).
• This unit must be isolated from the gas
supply system by closing its manual shut-off
valve during any pressure testing of the gas
supply piping system at test pressures equal
to or less than ½ PSIG (3.48 kPa).
14
Proper piping practice
CAUTION