A.O. Smith 104 Series, Инструкция по эксплуатации

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GAS PIPING
Conta F t your lo F al gas servi F e F ompany to ensure that adequate
gas servi F e is available and to review appli F able installation F odes
for your area
Size the main gas line in a FF ordan F e with Table 8 The ¿ gures shown
are for straight lengths of pipe at 0 5 in W C pressure drop, whi F h is
F onsidered normal for low pressure systems Note Fittings su F h as
elbows, tees and line regulators will add to the pipe pressure drop
Also refer to the latest version of the National Fuel Gas Code
S F hedule 40 Steel or Wrought Iron Pipe is the preferred material
for the gas line of this water heater It is imperative to follow the
sizing re F ommendations in the latest version of the National Fuel
Gas Code if Corrugated Stainless Steel Tubing (CSST) is used as
the gas line for this water heater
The heater is not intended for operation at higher than 14 0" W C -
natural gas, (1/2 pound per square in F h gage) supply gas pressure
Exposure to higher supply pressure may F ause damage to the
gas valve whi F h F ould result in ¿ re or explosion If overpressure
has o FF urred su F h as through improper testing of gas lines or
emergen F y malfun F tion of the supply system, the gas valve must be
F he F ked for safe operation Make sure that the outside vents on the
supply regulators and the safety vent valves are prote F ted against
blo F kage These are parts of the gas supply system, not the heater
Vent blo F kage may o FF ur during i F e storms
TABLE 8. MAXIMUM CAPACITY OF PIPE IN
CUBIC FEET OF GAS PER HOUR
(Based upon a Pressure Drop of 0 5 in F h Water Column and
0 6 Spe F i ¿F Gravity Gas and max gas pressure of 5 psig)
LENGTH
IN FEET
NOMINAL IRON PIPE SIZE (INCHES)
1/2 3/4 1 1 1/4 1 1/2 2 2 1/2 3 4
10 175 360 680 1,400 2,100 3,950 6,300 11,000 23,000
20 120 250 465 950 1,460 2,750 4,350 7,700 15,800
30 97 200 375 770 1,180 2,200 3,520 6 250 12 800
40 82 170 320 660 990 1,900 3,000 5,300 10,900
50 73 151 285 580 900 1,680 2,650 4,750 9,700
60 66 138 260 530 810 1,520 2,400 4,300 8,800
70 61 125 240 490 750 1,400 2,250 3,900 8,100
80 57 118 220 460 690 1,300 2,050 3,700 7,500
90 53 110 205 430 650 1,220 1,950 3,450 7,200
100 50 103 195 400 620 1,150 1,850 3,250 6,700
125 44 93 175 360 550 1,020 1,650 2,950 6,000
150 40 84 160 325 500 950 1,500 2,650 5,500
175 37 77 145 300 460 850 1,370 2,450 5,000
200 35 72 135 280 430 800 1,280 2,280 4,600
It is important to guard against gas valve fouling from F ontaminants in
gas ways Su F h fouling may F ause improper operation, ¿ re or explosion
If F opper supply lines are used they must be internally tinned and
F erti ¿ ed for gas servi F e Before atta F hing the gas line, be sure that
all gas pipe is F lean on the inside
To trap any dirt or foreign material in the gas supply line, a sediment
trap must be in
F orporated in the piping (see Figure 20) The sediment
trap must be readily a FF essible and not subje F t to freezing F onditions
Install in a FF ordan F e with re F ommendations of serving gas suppliers
Refer to the latest version of the National Fuel Gas Code
To prevent damage, F are must be taken not to apply too mu F h torque
when atta F hing gas supply pipe to gas valve inlet
Apply joint F ompounds (pipe dope) sparingly and only to the male
threads of pipe joints Do not apply F ompounds to the ¿ rst two threads
Use F ompounds resistant to the a F tion of lique ¿ ed petroleum gases
GAS METER SIZE – NATURAL GASES ONLY
Be sure the gas meter has suf ¿F ient F apa F ity to supply the full rated
gas input of the water heater as well as the requirements of all other
gas
¿ red equipment supplied by the meter If gas meter is too small, ask
the gas F ompany to install a larger meter having adequate F apa F ity
GAS PIPING AND SEDIMENT TRAP INSTALLATION
FIGURE 20.
GAS LINE LEAK TESTING
Fire and Explosion Hazard
Leak test before placing the water
heater in operation.
Disconnect gas piping and main gas
shutoff valve before leak testing.
Install sediment trap in accordance
with NFPA 54.
Use joint compound or Teflon tape
compatible with propane gas.
Any time work is done on the gas supply system perform a leak test
to avoid the possibility of
¿ re or explosion
1 For test pressures ex F eeding 1/2 psi (3 45 kPa) dis F onne F t the
water heater and its Main Gas Shutoff Valve from the gas supply
piping system during testing, see Figure 20
The gas supply line
must be F apped when dis F onne F ted from the water heater
2 For test pressures of 1/2 psi (3 45 kpa) or less, the water heater
need not be dis F onne F ted, but must be isolated from the supply
gas line by F losing the Main Gas Shutoff Valve during testing
3 Coat all supply gas line joints and F onne F tions upstream of the
water heater with a non- F orrosive soap and water solution to
test for leaks Bubbles indi F ate a gas leak Do not use mat F hes,
F andles, À ame or other sour F es of ignition for this purpose
4 Repair any leaks before pla F ing the water heater in operation
PURGING
Gas line purging is required with new piping or systems in whi F h air
has entered
Purging should be performed per the F urrent edition of NFPA 54 the
National Fuel Gas Code