28743-0-0711
Page 9
GAS SUPPLY
All gas piping must be installed in compliance with local codes and
utility regulations. In the absence of local codes the installation
must comply with NFCG NFPA 54/ANSI Z223.1.
Note:
Never use plastic pipe. Check to confirm whether your
local codes allow copper tubing or galvanized.
Where permitted, flexible gas connectors must be certified to the
following standards:
— ANS Z21.24 Appliance Connectors of Corrugated Metal Tub
-
ing and Fittings
— ANS Z21.45 Assembled Flexible Appliance Connectors of
Other Than All-Metal Construction
The above connectors may be used if acceptable by the author-
ity having jurisdiction. The state of Massachusetts requires that a
flexible appliance connector cannot exceed three feet in length.
A drip leg should be installed in the vertical gas supply pipe run to
the unit.
Manual Shut-off Valve
Some local regulations require the installation of a manual shut-off
valve and ground joint union external to the appliance. The shutoff
should be accessible for service and/or emergency use. Consult the
local utility or gas supplier for additional requirements regarding the
placement of the manual shut off valve. Compounds used on
threaded joints of gas piping shall be resistant to the action of liq
-
uefied petroleum gases.
Leak Testing
WARNING - FIRE OR EXPLOSION HAZARD
Never test for leaks with an open flame. Check all
connections using a commercially available soap so-
lution. A fire or explosion may result causing prop-
erty damage, personal injury or loss of life. Failure
to follow the safety warnings exactly could result in
serious injury, death or property damage.
After gas piping to the heater is complete, all connections must be
tested for gas leaks. This includes pipe connections at the main
gas valve, emergency shutoff valve and flexible gas connectors (if
applicable). The soap and water solution can be applied on each
joint or union using a small paintbrush. If any bubbling is observed,
the connection is not sealed adequately and must be retightened.
Repeat the tightening and soap check process until the bubbling
ceases.
Important Note:
When pressure testing the gas supply lines at pressures
greater than ½ psig (14 in. w.c.), the gas supply piping system
must be disconnected from the appliance to prevent damage
to the gas control valve. If the test pressure is less than or
equal to ½ psig (14 in. w.c.), close the manual shut-off valve.
Pressure Testing of the Gas Supply System
1. To check the inlet pressure to the gas valve, a 1/8 inch N.P.T.
plugged tapping, accessible for test gauge connection, must
be placed immediately upstream of the gas supply connection
to the appliance.
2. The appliance and its individual shutoff valve must be discon-
nected from the gas supply piping system during any pres-
sure testing of that system at test pressures in excess of 1/2
psig.
3. The appliance must be isolated from the gas supply piping
system by closing its individual manual shutoff valve during
any pressure testing of the gas supply piping system at test
pressures equal to or less than 1/2 psig.
Recommended Gas Pipe Diameter
Pipe Length
Schedule 40 Pipe
Inside Diameter
In Inches
Tubing, Type L
Outside Diameter
In Inches
Nat.
L.P.
Nat.
L.P.
0-10 feet
1/2
3/8
1/2
3/8
10-40 feet
1/2
1/2
5/8
1/2
40-100 feet
1/2
1/2
3/4
1/2
100-150 feet
3/4
1/2
7/8
3/4
