Sediment Traps; Gas Piping - A.O. Smith GCVT-40 Instruction Manual

Use pipe joint compound or teflon 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
FIGURE 12. GAS PIPING WITH
FLEXIBLE CONNECTOR.

SEDIMENT TRAPS

(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 13. GAS PIPING WITH ALL
BLACK IRON PIPE TO GAS CONTROL.
A sediment trap shall be installed as close to the inlet of the water
heater as practical at the time of water heater installation. The sediment
trap shall be either a tee fitting with a capped nipple in the bottom outlet
or other device recognized as an effective sediment trap. If a tee fitting
is used, it shall be installed in conformance with one of the methods of
installation shown in Figures 12 and 13.
Contaminants in the gas lines may cause improper operation of the gas
control valve that may result in fire or explosion. Before attaching the
gas line be sure that all gas pipe is clean on the inside. To trap any dirt
or foreign material in the gas supply line, a drip leg (sometimes called a
sediment trap) must be incorporated in the piping. The drip leg must be
readily accessible. Install in accordance with the "Gas Piping" section.
Refer to the current edition of the National Fuel Gas Code,
ANSI Z223.1/NFPA 54.
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