A.O. Smith GPVH-50 Water Heater User Manual


 
13
GAS PIPING
Make sure the gas supplied is the same type listed on the model
rating plate. The inlet gas pressure must not exceed 14 inch water
column (3.5 kPa) for natural and propane gas (L.P.). The minimum
inlet gas pressure shown on the rating plate is that which will permit
ring at rated input.
All gas piping must comply with local codes and ordinances or with the
National Fuel Gas Code (ANSI Z223.1/ NFPA-54) whichever applies.
Copper and brass tubing and ttings (except tin lined copper tubing)
shall not be used.
If the gas control valve is subjected to pressures exceeding 1/2 psi
(14 inches water column) (3.5 kPa), the damage to the gas control
valve could result in a re 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 suf cient size must be run to the water heater. Consult
the current edition of National Fuel Gas Code ANSI Z223.1/NFPA 54
and your gas supplier concerning pipe size.
There must be:
• A readily accessible manual shut off valve in the gas supply line
serving the water heater, and
• A drip leg (sediment trap) ahead of the gas control valve to help
prevent dirt and foreign materials from entering the gas control
valve.
• A exible 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 ame. Rinse
off soapy solution and wipe dry.
When installed at elevations above 7,700 feet (2,347 meters), input
rating should be reduced at the rate of 4 percent for each 1,000 feet
(305 meters) above sea level which requires replacement of the
burner ori ce in accordance with National Fuel Gas Code ANSI Z223.1/
NFPA 54. Contact your local gas supplier for further information.
Failure to replace the standard ori ce with a high altitude ori ce when
installed could result in improper and inef cient operation of the
appliance, producing carbon monoxide gas in excess of safe limits,
which could result in serious injury or death. Contact your gas supplier
for any speci c changes which may be required in your area.
Use pipe joint compound or te on tape marked as being resistant to
the action of petroleum [Propane (L.P.)] gases.
The appliance and its gas connection must be leak tested before
placing the appliance in operation.
The appliance and its individual Shut-off valve shall be disconnected
from the gas supply piping system during any pressure testing of that
system at test pressures in excess of 1/2 pound per square inch (14
inches water column) (3.5 kPa). It shall be isolated from the gas supply
piping system by closing its individual manual Shut-off valve during
any pressure testing of the gas supply piping system at test pressures
equal to or less than 1/2 pound per square inch (3.5 kPa).
Connecting the gas piping to the gas control valve of the water heater
can be accomplished by either of the two methods shown in Figures
12 and 13.
FIGURE 12. GAS PIPING WITH
FLEXIBLE CONNECTOR.
FIGURE 13. GAS PIPING WITH ALL
BLACK IRON PIPE TO GAS CONTROL VALVE.