Modine Manufacturing BAE 用户手册
5
Piping
1.
Installation of piping must be in accordance with local
codes, and ANSI Z223.1, “National Fuel Gas Code,” or
CAN/CGA-B149 in Canada. Do not use flexible connectors.
codes, and ANSI Z223.1, “National Fuel Gas Code,” or
CAN/CGA-B149 in Canada. Do not use flexible connectors.
2.
Piping to units should conform with local and national
requirements for type and volume and gas handled, and
pressure drop allowed in the line. Refer to Table 4, 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 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 1
allows for the usual number of fittings with a 0.3” W.C.
pressure drop. Where the gas supplied has a specific
gravity other than 0.60, apply the multiplying factor as given
in Table 2.
requirements for type and volume and gas handled, and
pressure drop allowed in the line. Refer to Table 4, 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 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 1
allows for the usual number of fittings with a 0.3” W.C.
pressure drop. Where the gas supplied has a specific
gravity other than 0.60, apply the multiplying factor as given
in Table 2.
3.
After threading and reaming the ends, inspect piping and
remove loose dirt and chips.
remove loose dirt and chips.
4.
Support piping so that no strains are imposed on unit or
controls.
controls.
5.
Use two wrenches when connecting piping to unit controls.
6.
Provide a sediment trap before each unit and in the line
where low spots cannot be avoided. (See Figure 4).
where low spots cannot be avoided. (See Figure 4).
7.
Take-off to unit should come from top or side of main to
avoid trapping condensate.
avoid trapping condensate.
8.
Piping, subject to wide temperature variations, should be
insulated.
insulated.
9.
Pitch piping up toward unit at least 1/4” per 15’ of horizontal
run.
run.
10. Compounds used on threaded joints of gas piping must be
resistant to action of liquefied petroleum gases.
11. Purge air before lighting unit by disconnecting pilot tubing at
combination gas control. In no case should line be purged
into heat exchanger.
into heat exchanger.
12. After installation, check system for gas leaks, using a soap
solution.
13. Install a ground joint union and a manual shut off valve
immediately upstream of the unit including a 1/8” NPT
plugged tapping accessible for test gage connection. (See
Figure 4).
plugged tapping accessible for test gage connection. (See
Figure 4).
14. Allow at least 5 feet of piping between any high pressure
regulator and unit control string.
15. 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)
The appliance should be isolated from the gas supply
piping system by closing its field installed manual shutoff
valve.
during any pressure testing in excess of 14” W.C. (1/2 psi)
The appliance should be isolated from the gas supply
piping system by closing its field installed manual shutoff
valve.
GAS
SUPPLY LINE
GAS
SUPPLY LINE
GROUND
JOINT
UNION
MANUAL
SHUT-OFF
VALVE
3"
MIN.
SEDIMENT
TRAP
PLUGGED
1/8" NPT TEST
GAGE CONNECTION
TO
CONTROLS
CAUTION
Gas pressure to unit heater controls must never exceed 14"
W.C. (1/2 psi).
W.C. (1/2 psi).
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).
appliance and its combination gas control must be isolated
during any pressure testing in excess of 14" W.C. (1/2 psi).
The appliance should be isolated from the gas supply piping
system by closing its field installed manual shut-off valve.
system by closing its field installed manual shut-off valve.
!
INSTALLATION
Figure 4
Recommended Piping
to Controls
Recommended Piping
to Controls
Table 2
Specific Gravity Conversion Factors
Specific Gravity Conversion Factors
Multiplying factors to be sued with table 1 when the specific
gravity of gas is other than 0.60.
gravity of gas is other than 0.60.
Table 1
Gas Pipe Capacities
Gas Pipe Capacities
In Cu. Ft. per Hour with Pressure Drop pf 0.3 in. W.C. with Specific Gravity 0.60.
NATURAL GAS
Specific
Gravity
Factor
0.55
1.04
0.60
1.00
0.65
0.962
PROPANE GAS
Specific
Gravity
Factor
1.50
0.633
1.53
0.626
1.60
0.612
1/2
3/4
1
1 1/4
1 1/2
2
3
4
6
8
15
76
218
440
750
1220
2480
6500
13880
38700
79000
30
73
152
285
590
890
1650
4700
9700
27370
55850
45
44
124
260
435
700
1475
3900
7900
23350
45600
60
50
105
190
400
610
1150
3250
6800
19330
39500
75
97
200
345
545
1120
3000
6000
17310
35300
90
88
160
320
490
930
2600
5400
15800
32250
105
80
168
285
450
920
2450
5100
14620
29850
120
158
270
420
860
2300
4800
13680
27920
150
120
242
380
710
2000
4100
12240
25000
180
128
225
350
720
1950
4000
11160
22800
210
205
320
660
1780
3700
10330
21100
240
190
300
620
1680
3490
9600
19740
270
178
285
580
1580
3250
9000
18610
300
170
270
545
1490
3000
8500
17660
450
140
226
450
1230
2500
7000
14420
600
119
192
380
1030
2130
6000
12480
Diameter of Pipe - Inches
Length of
Pipe in Ft.