282911-YIM-B-0807
8
Unitary Products Group
GAS PIPING
Proper sizing of gas piping depends on the cubic feet per
hour of gas flow required, specific gravity of the gas and the
length of run. National Fuel Gas Code Z223.1 or CAN/CGA
B149.1 or .2 should be followed in all cases unless super-
seded by local codes or gas company requirements. Refer to
Tables 5 and 6.
The heating value of the gas may differ with locality. The
value should be checked with the local gas utility.
NOTE:
There may be a local gas utility requirement specify-
ing a minimum diameter for gas piping. All units
require a 1/2 inch pipe connection at the gas valve.
GAS CONNECTION
The gas supply line can be routed through the hole located
on the left side of the unit. Refer to Figure 7 to locate these
access openings. Typical supply piping arrangements are
shown in Figure 5.
Gas piping recommendations:
1.
A drip leg and a ground joint union must be installed in
the gas piping.
2.
When required by local codes, a manual shut-off valve
may have to be installed outside of the unit.
3.
Use wrought iron or steel pipe for all gas lines. Pipe dope
should be applied sparingly to male threads only.
.
FIGURE 5 - EXTERNAL SUPPLY CONNECTION
EXTERNAL SHUT-OFF
1 / 2 x 1 / 2 G A S C O C K
1 / 2 x 1 / 2 U N I O N
A U T O M A T I C
G A S V A L V E
D R I P L E G
1 / 2 - 1 4 N P T
TABLE 5: NATURAL GAS PIPE SIZING CHART
1
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).
LENGTH
IN FEET
NOMINAL INCHES IRON PIPE SIZE
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
TABLE 6: PROPANE (LP) GAS PIPE SIZING
CHART
1
1.
Maximum capacity of pipe in thousands of BTU per hour (based
upon a pressure drop of 0.5 inch water column).
LENGTH
IN FEET
NOMINAL INCHES IRON PIPE SIZE
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
