37
Installation & Operation Manual
Table 6B Natural Gas Pipe Size Chart
TABLE - 6B
Capacity of Schedule 40 Metallic Pipe in Cubic Feet of Natural Gas Per Hour
(based on .60 specific gravity, 0.30" w.c. pressure drop)
Pipe
Size
(Inches)
Length of Pipe in Straight Feet
10
20
30
40
50
60
70
80
90
100
125
150
175
200
2
3,050
2,090
1,680
1,440
1,280
1,160
1,060
989
928
877
777
704
648
602
2 1/2
4,860
3,340
2,680
2,290
2,030
1,840
1,690
1,580
1,480
1,400
1,240
1,120
1,030
960
3
8,580
5,900
4,740
4,050
3,590
3,260
3,000
2,790
2,610
2,470
2,190
1,980
1,820
1,700
4
17,500 12,000
9,660
8,270
7,330
6,640
6,110
5,680
5,330
5,040
4,460
4,050
3,720
3,460
6
Gas connections
(continued)
Gas Pressure
The gas pressure must remain between 4 inches w.c. (.99 kPa)
minimum and 14 inches w.c. (3.5 kPa)maximum for Natural
gas and between 8 inches w.c. (2.0 kPa) minimum and 14
inches w.c. (3.5 kPa) maximum for LP gas during standby
(static) mode and while in operating (dynamic) mode. If an
in-line regulator is used, it must be a minimum of 10 feet (3
m) from the Power-fin boiler. It is very important that the gas
line is properly purged by the gas supplier or utility company.
Failure to properly purge the lines or improper line sizing, will
result in ignition failure.
Ignition problems are especially noticeable in NEW LP
installations and also in empty tank situations. This can also
occur when a utility company shuts off service to an area to
provide maintenance to their lines.
DO NOT adjust or attempt to measure gas
valve outlet pressure. Attempting to alter
or measure the gas valve outlet pressure
could result in damage to the valve causing
potential severe personal injury, death, or
substantial property damage.
Failure to follow all precautions could result
in fire, explosion, or death!
WARNING
WARNING
Gas valve replacement
The gas valve MUST NOT be replaced with a conventional gas
valve under any circumstances. As an additional safety feature,
the gas valves have flanged connections to the venturis and
blowers.
