Sediment Traps/Dirt Leg - Lochinvar POWER VENTED GAS HEATERS Installation And Operating Manual

Make sure the gas supplied is the same type listed on the
model rating plate. The inlet gas pressure must not exceed
14 inch w. c. (3.5 kPa) for natural gas and propane gas.
The minimum inlet gas pressure shown on the rating plate
is that which will permit fi 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). Copper or brass tubing and fi ttings (except tin lined
copper tubing) should not be used.
If the gas control valve/thermostat is subjected to pressures
exceeding 1/2 psi (3.5 kPa), the damage to the gas control
valve/thermostat could result in a fi 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 suffi 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 sediment trap (dirt leg) ahead of gas control valve/
thermostat to help prevent dirt and foreign materials
from entering the gas control valve/thermostat.
•
A fl exible gas connector or a ground joint union between
the shut-off valve and gas control valve/thermostat 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 fl ame. Repair and retest as required. When
fi nished, rinse off soapy solution and wipe dry.
WARNING
• Use joint compound or tape
compatible with propane.
• Leak test before operating
heater.
• Disconnect gas piping and
shut-off valve before pressure
testing system.
Use pipe joint compound or Tefl on tape marked as being
resistant to the action of 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 should be
disconnected from the gas supply piping system during
any pressure testing of that system at test pressures in
Fire and Explosion Hazard
excess of 1/2 psi (3.5 kPa). It should 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
psi (3.5 kPa).
Connecting gas piping to the gas control valve/thermostat
of water heater can be accomplished by either of two
methods shown in Figures 26 & 27.

SEDIMENT TRAPS/DIRT LEG

A sediment trap should be installed as close to the inlet of
the water heater as practical at the time of water heater
installation. The sediment trap should be either a tee fi tting
with a capped nipple in the bottom outlet or other device
recognized as an effective sediment trap. If a tee fi tting is
used, it should be installed in conformance with one of the
methods of installation shown in Figures 26 & 27.
Contaminants in the gas lines may cause improper
operation of the gas control valve/thermostat that may
result in fi re or explosion. Before attaching the gas line be
sure that all gas pipe is clean on the inside. To trap any
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Figure 26
Figure 27
WARNING
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 NFPA54.
25