Gas Supply Regulator; Gas Line Installation - A.O. Smith 100 Series Installation And Operating Manual

GAS SUPPLY REGULATOR

The maximum allowable gas supply pressure for this water heater is
14" w.c. (3.5 kPa). Install a positive lock-up gas pressure regulator
in the gas supply line if inlet gas pressure can exceed 14" w.c.
(3.5 kPa) at any time. Regulators must be sized/used according to
manufacturer's specifications.
If a positive lock-up regulator is required follow these instructions:
1. Positive lock-up gas pressure regulators must be rated at or
above the input Btu/hr rating of the water heater they supply.
2. Supply gas regulators shall have inlet and outlet connections
not less than the minimum supply gas line size for the water
heater they supply.
3. Positive lock-up gas pressure regulator(s) should be installed
no closer than 1 m (3') and no farther than 2.4 m (8') from the
water heater's inlet gas connection.
4. After installing the positive lock-up gas pressure regulator(s) an
initial nominal supply pressure setting of 7.0" w.c. (1.74 kPa)
for Natural Gas and 11.0" w.c. (2.74 kPa) for Propane (LP)
while the water heater is operating is recommended and will
generally provide good water heater operation. Some additional
adjustment may be required later to maintain a steady gas
supply pressure.
5. When installing multiple water heaters in the same gas supply
system it is recommended that individual positive lock-up gas
pressure regulators be installed at each unit.
All gas piping must comply with local codes and ordinances or with
current editions of the Natural Gas and Propane Installation Code" B149.1.
Copper or brass tubing and fittings (except tin lined copper tubing)
shall not be used.
If the gas control valve is subjected to pressures exceeding 1/2 psi
(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 water heaters is used,
also turn off the gas at each water heater. 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 the Natural Gas and Propane Installation Code B149.1
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 sediment trap ahead of the gas control valve to help prevent
dirt and foreign materials from entering the gas control valve.
• A ground joint union of proper size between the manual shut off
valve and gas 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.

GAS LINE INSTALLATION

Contact your local gas utility company to ensure that adequate gas
service is available and to review applicable installation codes for
your area.
Be sure that the gas meter has sufficient capacity to supply the
rated gas input of the water heater as well as the requirements of
all other gas fired equipment supplied by the meter. If the gas meter
is undersized, the gas company will have to install a properly sized
gas meter.
Make sure the gas supplied is the same type listed on the water
heaters rating label.
The gas piping must be installed according to all local and provincial
codes or in absence of local and provincial codes with the current
edition of the Natural Gas and Propane Installation Code B149.1.
Schedule 40 Steel or Wrought Iron Pipe is the preferred material for
the gas line of this water heater.
Consult the National Fuel Gas Code for the recommended gas pipe size
of other materials.
WARNING
Follow the instructions below and see Figure 41 for gas piping
installation.
1. Apply thread sealing compounds (pipe dope/Teflon
sparingly and only to the male threads of the pipe joints. Do not
apply sealing compound to the first two threads. Use pipe dope
or Teflon © tape marked as being resistant to the action of liquid
petroleum (LP/propane) gases.
2. Install a readily accessible manual shut-off valve in the gas supply
line as recommended by the local utility. Know the location of this
valve and how to turn off the gas to this unit.
3. Install a sediment trap as shown. The sediment trap must be no
less than 75 mm (3") long for the accumulation of dirt, foreign
material and water droplets.
35
WARNING
Fire and Explosion Hazard
• Use joint compound or tape
compatible with natural gas
and propane.
• Leak test before operating
heater.
• Disconnect gas piping and
shut-off valve before pressure
testing system.
Fire and Explosion Hazard
• Contaminants in gas lines can
cause fire or explosion.
• Clean all gas piping before
installation.
• Install sediment trap in accor-
dance with B149.1.
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