Pressure Test Gas Piping; High Altitude Derate - Lennox LGM036 Installation Instructions Manual

BOTTOM ENTRY GAS PIPING COMPLETED
GROUND
JOINT UNION
STREET
ELBOW
7" NIPPLE
2-1/2" NIPPLE
DRIP LEG
Grommets for both gas pipe openings are field provided.
FIGURE 12
Pressure Test Gas Piping (Gas Units)
When pressure testing gas lines, the gas valve must
be disconnected and isolated. Gas valves can be
damaged if subjected to more than 0.5 psig (3.48kPa).
See figure 13.
NOTE-Codes may require that manual main shut-off
valve and union (furnished by installer) be installed in gas
line external to unit. Union must be of the ground joint
type.
After all connections have been made, check all piping
connections for gas leaks. Also check existing unit gas
connections up to the gas valve; loosening may occur
during installation. Use a leak detection solution or other
preferred means. Do not use matches candles or other
sources of ignition to check for gas leaks.
CAUTION
Some soaps used for leak detection are corrosive
to certain metals. Carefully rinse piping thoroughly
after leak test has been completed. Do not use
matches, candles, flame or othe sources of ignition
to check for gas leaks.
WARNING
Danger of explosion. Can cause injury
or product or property damage. Do not
use matches, candles, flame or other
sources of ignition to check for leaks.
LGM/LCM036, 048, 060, 074
TO GAS
VALVE
TO GAS
SUPPLY
MANUAL MAIN
SHUT-OFF VALVE
Page 9
NOTE-In case emergency shut down is required, turn off
the main manual shut-off valve and disconnect main
power to unit. These devices should be properly labeled
by the installer.
PRESSURE TEST GAS LINE
MANUAL MAIN
SHUT-OFF VALVE
GAS VALVE
FIGURE 13

High Altitude Derate

Locate the high altitude conversion sticker in the unit
literature bag. Fill out the conversion sticker and affix next
to the unit nameplate.
Refer to table 2 for high altitude adjustments.
TABLE 2
HIGH ALTITUDE DERATE
Altitude Ft.*
2000-4500
4500 And Above Derate 2% / 1000 Ft. Above Sea Level
*Units installed at 0-2000 feet do not need to be modified.
NOTE ‐ This is the only permissible derate for these units.
CAP
Gas Manifold Pressure
See Unit Nameplate