Modine Manufacturing PV Installation And Service Manual page 7

I I N N S S T T A A L L L L A A T T I I O O N N
P P i i p p i i n n g g
!
C C A A U U T T I I O O N N
Gas pressure to unit heater controls must never exceed
14" 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).
The appliance 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.
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.
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 5a, 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 3.
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 4.
T T a a b b l l e e 3 3 – – G G a a s s P P i i p p e e C C a a p p a a c c i i t t i i e e s s
In Cu. Ft. per Hour with Pressure Drop pf 0.3 in. W.C. with Specific Gravity 0.60.
L L e e n n g g t t h h o o f f
P P i i p p e e i i n n F F t t . .
1 1 / / 2 2 3 3 / / 4 4
1 1 5 5 76 218
3 3 0 0
73 152
4 4 5 5 44 124
6 6 0 0
50 105
7 7 5 5 97
9 9 0 0
88
1 1 0 0 5 5 80
1 1 2 2 0 0
1 1 5 5 0 0
1 1 8 8 0 0
2 2 1 1 0 0
2 2 4 4 0 0
2 2 7 7 0 0
3 3 0 0 0 0
4 4 5 5 0 0
6 6 0 0 0 0
T T a a b b l l e e 4 4
S S p p e e c c i i f f i i c c G G r r a a v v i i t t y y C C o o n n v v e e r r s s i i o o n n F F a a c c t t o o r r s s
Multiplying factors to be used with table 1 when the specific
gravity of gas is other than 0.60.
N N a a t t u u r r a a l l G G a a s s
S S p p e e c c i i f f i i c c
G G r r a a v v i i t t y y F F a a c c t t o o r r
0.55 1.04
0.60 1.00
0.65 0.962
D D i i a a m m e e t t e e r r o o f f P P i i p p e e - - I I n n c c h h e e s s
1 1 1 1 - - 1 1 / / 4 4 1 1 - - 1 1 / / 2 2 2 2
440 750 1220 2480
285 590 890 1650
260 435 700 1475
190 400 610 1150
200 345 545 1120
160 320 490 930
168 285 450 920
158 270 420 860
120 242 380 710
128 225 350 720
205 320 660
190 300 620
178 285 580
170 270 545
140 226 450
119 192 380
P P r r o o p p a a n n e e G G a a s s
S S p p e e c c i i f f i i c c
G G r r a a v v i i t t y y F F a a c c t t o o r r
1.50 0.633
1.53 0.626
1.60 0.612
3. After threading and reaming the ends, inspect piping and
remove loose dirt and chips.
4. Support piping so that no strains are imposed on unit or
controls.
5. Use two wrenches when connecting piping to unit controls.
6. Provide a drip sediment trap before each unit and in the line
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.
8. Piping, subject to wide temperature variations, should be
insulated.
9. Pitch piping up toward unit at least 1/4" per 15' of horizontal
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.
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).
14. Allow at least 5 feet of piping between any high pressure
regulator and unit control string.
15. 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.
3 3 4 4 6 6
6500 13880 38700 79000
4700 9700 27370 55850
3900 7900 23350 45600
3250 6800 19330 39500
3000 6000 17310 35300
2600 5400 15800 32250
2450 5100 14620 29850
2300 4800 13680 27920
2000 4100 12240 25000
1950 4000 11160 22800
1780 3700 10330 21100
1680 3490 9600 19740
1580 3250 9000 18610
1490 3000 8500 17660
1230 2500 7000 14420
1030 2130 6000 12480
F F i i g g u u r r e e 4 4
R R e e c c o o m m m m e e n n d d e e d d P P i i p p i i n n g g t t o o C C o o n n t t r r o o l l s s
GAS
SUPPLY LINE
GAS
SUPPLY LINE
3"
MIN.
SEDIMENT
TRAP
8 8
GROUND
MANUAL
JOINT
SHUT-OFF
UNION
VALVE
TO
CONTROLS
PLUGGED
1/8" NPT TEST
GAGE CONNECTION
7 7