Gas Connections - Modine HDS Manuel D'installation Et D'entretien

INSTALLATION

Gas Connections

WARNING
1. All field gas piping must be pressure/leak tested prior to
operation. Never use an open flame. Use a soap solution
or equilavent for testing.
2. Gas pressure to appliance controls must never exceed 14"
W.C. (1/2 psi).
3. 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 duel rated units.
CAUTION
1. Purging of air from gas lines should be performed as
described in ANSI Z223.1 - latest edition "National Fuel
Gas Code", or in Canada CSA B149.1 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%.
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 149.1.
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 13.1 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
Table 9.1
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 - 0.60
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
the length of pipe necessary, determine the pipe diameter
from Table 9.1. 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
9.1 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 9.1). Verify the manual shut-off valve is
gas tight on an anual basis.
4. Provide a sediment trap before each unit in the line where
low spots cannot be avoided. (See Figure 9.1).
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.
Figure 9.1
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.
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
GAS
GROUND
MANUAL
JOINT
SHUT-OFF
UNION
VALVE
CONTROLS
PLUGGED
1/8" NPT TEST
GAGE CONNECTION
SEDIMENT
TRAP
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
TO
2"
Propane
1922
1323
1040
914
800
725
662
586
548
491
447
9