Gas Connections - Modine Manufacturing PTS Series Installation And Service Manual

InsTAllATIon - gAs ConneCTIons

gAs ConneCTIons

W ARNING
1. 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.
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 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.
IMPOR T ANT
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 11.1 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 11.2. 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 11.2
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 11.1).
4. Provide a sediment trap before each unit in the line where
low spots cannot be avoided. (See Figure 11.1).
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 11.1 - recommended sediment Trap/manual
shut-off valve Installation - side or Bottom gas
Connection

GAS
SUPPLY LINE
MANUAL
SHUT-OFF
VALVE
GAS
SUPPLY LINE
3" 1/8" NPT TEST
MIN. GAGE CONNECTION
SEDIMENT
TRAP
Table 11.1 - manifold Pressure & gas Consumption
model manifold Pressure
size ("W.C.):
CFH
150
Gal/Hr.Propane
Orifice Drill Size
CFH
175 Gal/Hr.Propane
Orifice Drill Size
CFH
200
Gal/Hr.Propane
Orifice Drill Size
CFH
250
Gal/Hr.Propane
Orifice Drill Size
CFH
300 Gal/Hr.Propane
Orifice Drill Size
CFH
350
Gal/Hr.Propane
Orifice Drill Size
CFH
400 Gal/Hr.Propane
Orifice Drill Size
Table 11.2 - gas Pipe Capacities - natural gas
Pipe
length (ft)
1/2" 3/4"
10
132 278
20 92 190
30 73 152
40 63 130
50 56 115
60 50 105
70
46
80
43
100
38
125 34
150 31

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.
‚ 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.
6-561.4
GROUND
JOINT
UNION
TO
CONTROLS
PLUGGED

Manual shut-off valve is in the
"OFF" position when handle is
perpendicular to pipe.
natural Propane
# of
3.5 10
Orifices
142.9 60.0
n/a 1.6 6
42 53
166.7 70.0
n/a 1.9 7
42 53
190.5 80.0
n/a 2.2 7
38 52
238.1 100.0
n/a 2.7 9
39 1.55mm
285.7 120.0
n/a 3.3 9
35 1.75mm
333.3 140.0
n/a 3.8 12
38 52
381.0 160.0
n/a 4.4 12
35 1.75mm
natural gas
1" 1-1/4" 1-1/2"
520 1050 1600 3050
350 730 1100 2100
285 590 890 1650
245 500 760 1450
215 440 670 1270
195 400 610 1150
96 180 370 560 1050
90 170 350 530
79 150 305 460
72 130 275 410
64 120 250 380
➀ ‚
2"
930
870
780
710
11