14
6-563.7
InsTAllATIon - gAs ConneCTIons
gAs ConneCTIons
1. Installation of piping must conform with local building codes,
or in the absence of local codes, with the National Fuel Gas
Code, ANSI Z223.1 (NFPA 54) - latest Edition. In Canada,
installation must be in accordance with CSA-B149.1.
2. Piping to units should conform with local and national
requirements for type and volume of gas handled, and
pressure drop allowed in the line. Refer to Table 14.1 to
determine the cubic feet per hour (CFH) for the type of gas
and size of unit to be installed. Using this CFH value and the
length of pipe necessary, determine the pipe diameter from
Table 14.2. Where several units are served by the same
main, the total capacity, CFH and length of main must be
considered. Avoid pipe sizes smaller than 1/2". Table 14.2
allows for a 0.3" W.C. pressure drop in the supply pressure
from the building main to the unit. The inlet pressure to the
unit must be 6-7" W.C. for natural gas and 11-14" W.C. for
propane gas. When sizing the inlet gas pipe diameter, make
sure that the unit supply pressure can be met after the 0.3"
W.C. has been subtracted. If the 0.3" W.C. pressure drop is
too high, refer to the Gas Engineer’s Handbook for other gas
pipe capacities.
3. Install a ground joint union with brass seat and a manual
shut-off valve adjacent to the unit for emergency shut-off and
easy servicing of controls, including a 1/8" NPT plugged
tapping accessible for test gauge connection (see Figure 14.1).
4. Use 2 wrenches when connecting field piping to units.
5. Provide a sediment trap before each unit in the line where
low spots cannot be avoided. (see Figure 14.1).
6. When pressure/leak testing, pressures above 11" W.C.
(1/2 psi), close the field installed shut-off valve, disconnect
the appliance and its combination gas control from the gas
supply line, and plug the supply line before testing. When
testing pressures 14" W.C. (1/2 psi) or below, close the
manual shut-off valve on the appliance before testing.
figure 14.1 - recommended sediment Trap/manual
shut-off valve Installation - side or Bottom gas
Connection
➀
GAS
SUPPLY LINE
GAS
SUPPLY LINE
GROUND
JOINT
UNION
MANUAL
SHUT-OFF
VALVE
3"
MIN.
SEDIMENT
TRAP
PLUGGED
1/8" NPT TEST
GAUGE CONNECTION
TO
CONTROLS
➀
Manual shut-off valve is in the
“OFF” position when handle is
perpendicular to pipe.
Pipe
length (ft.)
natural gas
1/2"
3/4"
1"
1-1/4" 1-1/2"
2"
10
132
278
520
1050 1600 3050
20
92
190
350
730
1100 2100
30
73
152
285
590
890
1650
40
63
130
245
500
760
1450
50
56
115
215
440
670
1270
60
50
105
195
400
610
1150
70
46
96
180
370
560
1050
80
43
90
170
350
530
930
100
38
79
150
305
460
870
125
34
72
130
275
410
780
150
31
64
120
250
380
710
Table 14.2 - gas Pipe Capacities - natural gas
➀ ➁
➀
Capacities in cubic feet per hour through Schedule 40 pipe with maximum
0.3" W.C. pressure drop with up to 14" W.C. gas pressure. Specific gravity is 0.60
for natural gas and 1.50 for propane gas.
➁
For pipe capacity with propane gas, divide natural gas capacity by 1.6. Example:
What is the propane gas pipe capacity for 60 feet of 1-1/4" pipe? The natural gas
capacity is 400 CFH. Divide by 1.6 to get 250 CFH for propane gas.
Table 14.1 - sea level manifold Pressure &
gas Consumption
WARNING
1. Installation must conform with local building codes or in
the absence of local codes, with the National Fuel Gas
Code, ANSI Z223.1 (NFPA 54) - latest edition. In Canada
installation must be in accordance with CSA B149.1.
2. All field gas piping must be pressure/leak tested prior to
operation. Never use an open flame. Use a soap solution
or equivalent for testing.
3. Gas pressure to appliance controls must never exceed
14" W.C. (1/2 psi).
4. To reduce the opportunity for condensation, the minimum
sea level input to the appliance, as indicated on the serial
plate, must not be less than 5% below the rated input, or
5% below the minimum rated input of dual rated units.
CAUTION
1. Purging of air from gas lines should be performed as
described in the National Fuel Gas Code, ANSI Z223.1
(NFPA 54) - latest edition, or in Canada CSA-B149 codes.
2. When leak testing the gas supply piping system, the
appliance and its combination gas control must be isolated
during any pressure testing in excess of 14" W.C. (1/2 psi).
3. The unit should be isolated from the gas supply piping
system by closing its field installed manual shut-off
valve.This manual shut-off valve should be located within
6' of the heater.
4. Turn off all gas before installing appliance.
ImpORTANT
To prevent premature heat exchanger failure, the input to
the appliance, as indicated on the serial plate, must not
exceed the rated input by more than 5%.
natural
Propane
model
size
manifold Pressure
(
"W.C.):
3.5
10
# of
orifices
55
CFH
54.0
22.1
4
Gal/Hr. Propane
n/a
0.61
Orifice Drill Size
50
1.10 mm
65
CFH
65.6
26.3
5
Gal/Hr. Propane
n/a
0.73
Orifice Drill Size
1.75 mm
57
85
CFH
81.0
34.0
5
Gal/Hr. Propane
n/a
0.9
Orifice Drill Size
47
1.25 mm
110
CFH
105.0
44.0
5
Gal/Hr. Propane
n/a
1.2
Orifice Drill Size
43
54
135
CFH
128.6
54.0
6
Gal/Hr. Propane
n/a
1.5
Orifice Drill Size
43
54
156
CFH
147.6
62.0
6
Gal/Hr. Propane
n/a
1.7
Orifice Drill Size
41
1.50 mm
180
CFH
171.4
72.0
7
Gal/Hr. Propane
n/a
2.0
Orifice Drill Size
41
53
215
CFH
204.8
86.0
9
Gal/Hr. Propane
n/a
2.4
Orifice Drill Size
42
54
260
CFH
247.6
104.0
9
Gal/Hr. Propane
n/a
2.9
Orifice Drill Size
38
52
310
CFH
295.2
124.0
12
Gal/Hr. Propane
n/a
3.4
Orifice Drill Size
41
53
