Gas Piping - Lochinvar LTN07575 Instruction Manual

GAS PIPING

Contact your local gas service company to ensure
that adequate gas service is available and to review
applicable installation codes for your area.
Size the main gas line in accordance with
. The sizes shown are for straight lengths of pipe
Table 3
at 0.5 in. W.C. pressure drop, which is considered normal
for low pressure systems. Note: Fittings such as elbows,
tees and line regulators will add to the pipe pressure
drop. Also refer to the current editions of the
.
Gas Code (NFPA 54)
Make sure gas supplied is same type listed on model
rating plate. The inlet gas pressure must not exceed 14
inch water column (2.6 kPa) for natural and propane
(L.P.) gas. The minimum inlet gas pressure shown on
rating plate is that which will permit firing at rated input.
If the gas control valve is subjected to pressures
exceeding 1/2 pound per square inch (3.5 kPa), the
damage to the gas control valve could result in a fire or
explosion from leaking gas.
If the main gas line shut-off serving all gas appliances is
used, also turn "off" the gas at each appliance. Leave all
gas appliances shut "off" until the water heater installation
is complete.
A gas line of sufficient size must be run to the water
heater. Consult the current edition of
Gas Code ANSI Z223.1/NFPA 54
concerning pipe size.
The gas piping must include the following:
• A readily accessible manual shut off valve in the gas
supply line serving the water heater, and
• A sediment trap ahead of the gas control valve to help
prevent dirt and foreign materials from entering the
gas control valve.
and
Table 2
National Fuel
National Fuel
and your gas supplier
• A flexible gas connector or a ground joint union
between the shut off valve and control valve to permit
servicing of the unit.
Be sure to check all the gas piping for leaks before
lighting the water heater. Use a soapy water solution, not
a match or open flame. Rinse off soapy solution and wipe
dry.
The minimum inlet gas pressure shown on the rating
plate is that which will permit firing at the rated input.
GAS SUPPLY LINE SIZES (IN INCHES)* MAXIMUM CAPACITY
OF PIPE IN CUBIC FEET PER HOUR
TABLE 2. INPUT IN THOUSANDS (BTU/HR)
LENGTH
NOMINAL IRON PIPE SIZES (INCHES)
IN
1/2" 3/4" 1"
FEET
10 175 360 680
20 120 250 465
30 97 200 375
40 82 170 320
50 73 151 285
60 66 138 260
70 61 125 240
80
57 118 220
90 53 110 205
100 50 103 195
125 44 93 175
150 40 84 160
175 37 77 145
200 35 72 135
TABLE 3. INPUT IN KW
LENGTH
NOMINAL IRON PIPE SIZES (INCHES)
IN
METERS
1/2" 3/4" 1"
3 51 105 199
6 35 73 142
9 28 59 110
12 24 50 94
15 21 44 83
18 19 40 76
21 18 37 70
24 17 35 64
27 16 32 60
31 15 30 57
38 13 27 51
46 12 25 47
53 11 23 42
61 10 21 40
21
1 1/4" 1 1/2" 2" 2 1/2" 3"
1400 2100 3960 6300 11000
950 1460 2750 4360 7700
770 1180 2200 3520 6250
660 990 1900 3000 5300
580 900 1680 2650 4750
530 810 1520 2400 4300
490 750 1400 2250 3900
460 690 1300 2050 3700
430 650 1220 1950 3450
400 620 1150 1850 3250
360 550 1020 1650 2950
325 500 950 1500 2650
300 460 850 1370 2450
800
280 430 1280 2280
1 1/4" 1 1/2" 2" 2 1/2" 3"
410 615 1160 1845 3221
278 428 805 1277 2255
225 346 644 1031 1830
193 290 556 878 1552
170 264 492 776 1391
155 237 445 703 1259
143 220 410 659 1142
135 202 381 600 1083
126 190 357 571 1010
117 182 337 542 952
105 161 299 483 864
95 146 278 439 776
88 135 249 401 717
82 126 234 375 688
4"
23000
15800
12800
10900
9700
8800
8100
7500
7200
6700
6000
5500
5000
4600
4"
6735
4626
3748
3192
2840
2577
2372
2196
2108
1962
1757
1610
1464
1347