York R-410A Flue Vent Hood, Natural Gas Pipe Sizing Chart1, Propane LP Gas Pipe Sizing Chart1

279550-YIM-A-0207

Table 7: Natural Gas Pipe Sizing Chart1

Length		Nominal Inches Iron Pipe Size
In Feet	1/2”		3/4”	1”	1-1/4”
10	132		278	520	1,050
20	92		190	350	730
30	73		152	285	590
40	63		130	245	500
50	56		115	215	440
60	50		105	195	400
70	46		96	180	370
80	43		90	170	350
90	40		84	160	320
100	38		79	150	305

1.Maximum capacity of pipe in cubic feet of gas per hour (based upon a pressure drop of 0.3 inch water column and 0.6 specific gravity gas).

Table 8: Propane (LP) Gas Pipe Sizing Chart1

Length		Nominal Inches Iron Pipe Size
In Feet	1/2”		3/4”	1”	1-1/4”
10	275		567	1,071	2,205
20	189		393	732	1,496
30	152		315	590	1,212
40	129		267	504	1,039
50	114		237	448	913
60	103		217	409	834
70	96		196	378	771
80	89		185	346	724
90	83		173	322	677
100	78		162	307	630

1.Maximum capacity of pipe in thousands of BTU per hour (based upon a pressure drop of 0.5 inch water column).

If flexible stainless steel tubing is allowed by the authority having jurisdiction, wrought iron or steel pipe must be installed at the gas valve and extend a minimum of two (2) inches outside of the unit casing.

Natural gas may contain some propane. Propane being an excellent solvent, will quickly dissolve white lead or most standard commercial compounds. Therefore, a special pipe dope must be applied when wrought iron or steel pipe is used. Shellac base compounds such as gaskoloc or stalastic, and compounds such as rectorseal # 5, Clyde’s or John Crane may be used.

4.All piping should be cleaned of dirt and scale by hammering on the outside of the pipe and blowing out the loose dirt and scale. Before initial start-up, be sure that all of the gas lines external to the unit have been purged of air.

5.The gas supply should be a separate line and installed in accordance with all safety codes as prescribed under

Limitations, shown on Page 3. After the gas connections have been completed, open the main shut-off valve admitting normal gas pressure to the mains. Check all joints for leaks with soap solution or other material suitable for the purpose. NEVER USE A FLAME.

FIRE OR EXPLOSION HAZARD

Failure to follow the safety warning exactly could result in serious injury, death or property damage.

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. A fire or explosion may result causing property damage, personal injury or loss of life.

6.The furnace must be isolated from the gas supply piping system by closing its individual manual shut-off valve before conducting any pressure testing of the gas supply piping system at test pressures equal to or less than 1/2 psig (3.48 kPa).

Flue Vent Hood

The flue vent hood with screen is shipped loose. This hood must be installed to assure proper unit operation. The hood must be fastened to the outside of the side gas control/electrical compartment with the screws provided in the bag attached to the inside of the gas control/electrical compartment, see Figure 13.

Flue hood surfaces may be hot.

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Figure 13: Flue Vent Outlet Air Hood

The flue exhaust hood must be properly installed and within the recommended clearances. Further commu- nications and action must be given to the home or building owner(s) to eliminate any unauthorized human contact around this area during the heating cycle. Flue hood surface and the immediate area reach high tem- peratures during the heating cycle.

16 Unitary Products Group