Modine HD Serie Manuel D'installation Et D'entretien page 15

InsTAllATIon - gAs ConneCTIons
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%.
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 15.1 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 15.2. 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 15.2
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 15.1).
4. Provide a sediment trap before each unit in the line where
low spots cannot be avoided. (See Figure 15.1).
5. When Pressure/Leak testing, pressures above 14" 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.
Table 15.2
gas pipe Capacities
gas pipe Capacities (up to 14" W.C. gas pressure through schedule 40 pipe)
length
of pipe
1/2"
(feet) Natural Propane
10 132 83
20 92 58
30 73 46
40 63 40
50 56 35
60 50 32
70 46 29
80 43 27
100 38 24
125 34 21
150 31 20
Cubic feet per Hour with pressure drop of 0.3" W.C.
natural gas - specific gravity - 0.0
propane gas - specific gravity - 1.50
3/4"
Natural Propane Natural
278 175 520
190 120 350
152 96 285
130 82 245
115 82 215
105 66 195
96 60 180
90 57 170
79 50 150
72 45 130
64 40 120
figure 15.1
recommended sediment Trap/manual shut-off valve
Installation - side or Bottom gas Connection
SUPPLY LINE
GAS
SUPPLY LINE
3"
MIN.
➀
Manual shut-off valve is in the "OFF" position when handle is perpendicular to pipe.
Table 15.1 manifold pressure & gas Consumption
model BTu/Cu. ft.
size specific gravity
manifold pressure In. W.C.
CFH
Gal/Hr. Propane
30
Sec/cu. ft.
Orifice Drill Size
CFH
Gal/Hr. Propane
45
Sec/cu. ft.
Orifice Drill Size
CFH
Gal/Hr. Propane
0
Sec/cu. ft.
Orifice Drill Size
CFH
Gal/Hr. Propane
75
Sec/cu. ft.
Orifice Drill Size
CFH
Gal/Hr.Propane
100
Sec/cu.ft.
Orifice Drill Size
CFH
Gal/Hr.Propane
125
Sec/cu.ft.
Orifice Drill Size
pipe diameter
1" 1-1/4"
Propane Natural Propane
328 1050 662
221 730 460
180 590 372
154 500 315
135 440 277
123 400 252
113 370 233
107 350 221
95 305 192
82 275 173
76 250 158
6-583.2
GAS
GROUND
MANUAL
JOINT
SHUT-OFF
UNION
VALVE
CONTROLS
PLUGGED
1/8" NPT TEST
GAGE CONNECTION
SEDIMENT
TRAP
natural propane
1050 2500 no. of
0.0 1.53 orifices
3.5 10.0
28.6 12.0
.33
126 300
49 56
42.9 18.0
.50
84 200
49 56
57.1 24.0
.66
63 150
49 56
71.4 30.0
.83
50 180
49 56
95.2 40
1.09
38 90
45 55
119 50
1.37
30 72
42 53
1-1/2"
Natural Propane Natural
1600 1008 3050
1100 693 2100
890 561 1650
760 479 1450
670 422 1270
610 384 1150
560 353 1050
530 334 930
460 290 870
410 258 780
380 239 710
➀
TO
2
3
4
5
5
5
2"
Propane
1922
1323
1040
914
800
725
662
586
548
491
447
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