A95235
→ Fig. 10—Horizontal Installation on Blocks
AIRFLOW
12″
4″ D
FILTER RETAINERS
Fig. 11—Horizontal Filter Arrangement
Table 4—Filter Retainer (In.)
FURNACE CASING WIDTH | FILTERS | D |
(2) 14 X 20 X 1 | ||
(2) 14 X 20 X 1 | ||
21 | (2) 16 X 20 X 1 | |
(2) 16 X 20 X 1 | ||
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If flexible connector is required or allowed by authority having jurisdiction, black iron pipe shall be installed at gas valve and extend a minimum of 2 in. outside furnace casing.
Use the proper length of pipes to avoid stress on gas control manifold. A failure to follow this warning could result in a gas leak causing fire, explosion, personal injury, or death.
Use a backup wrench at furnace gas control when connecting gas pipe to furnace to avoid damaging gas controls or manifold.
Never purge a line into a combustion chamber. Never use matches, candles, flame, or other sources of ignition to check for gas leakage. Use a
Joint compounds (pipe dope) should be applied sparingly and only to male threads of joints. This pipe dope must be resistant to action of propane gas.
AIRFLOW
INSTALLATION
POSITION
OF FILTERS
PLENUM
ACCESS DOOR
Fig. 12—Downflow Filter Arrangement A88486
Table 5—Maximum Capacity of Pipe*
NOMINAL | INTERNAL |
| LENGTH OF PIPE (FT) |
| |||
IRON PIPE | DIAMETER |
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10 |
| 20 | 30 | 40 | 50 | ||
SIZE (IN.) | (IN.) |
| |||||
1/2 | 0.622 | 175 |
| 120 | 97 | 82 | 73 |
3/4 | 0.824 | 360 |
| 250 | 200 | 170 | 151 |
1 | 1.049 | 680 |
| 465 | 375 | 320 | 285 |
1.380 | 1400 |
| 950 | 770 | 660 | 580 | |
1.610 | 2100 |
| 1460 | 1180 | 990 | 900 | |
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*Cubic ft of gas per hr for gas pressures of 0.5 psig
Install accessible manual shutoff valve upstream of furnace gas controls and within 72 in. of furnace. A
Install sediment trap in riser leading to furnace. The trap can be installed by connecting a tee to riser leading from furnace. Connect capped nipple into lower end of tee. The capped nipple should extend below level of gas controls. (See Fig. 13.)
Piping should be pressure tested in accordance with local and national plumbing and gas codes before furnace has been attached. If test pressure exceeds 0.5 psig
After all connections have been made, purge lines and check for gas leakage with regulated gas supply pressure.
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