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12821-2-0903
Recommended Gas Pipe Diameter
Pipe Length
Schedule 40 Pipe
Tubing, Type L
(Feet)
Inside Diameter
Outside Diameter
Nat.
L.P.
Nat.
L.P.
0-10
1/2"
3/8"
1/2"
3/8"
1.3 cm
1.0 cm
1.3 cm
1.0 cm
10-40
1/2"
1/2"
5/8"
1/2"
1.3 cm
1.3 cm
1.6 cm
1.3 cm
40-100
1/2"
1/2"
3/4"
1/2"
1.3 cm
1.3 cm
1.9 cm
1.3 cm
100-150
3/4"
1/2"
7/8"
3/4"
1.9 cm
1.3 cm
2.2 cm
1.9 cm
Note: Never use plastic pipe. Check to confirm whether your local
codes allow copper tubing or galvanized.
Note: Since some municipalities have additional local codes, it is
always best to consult your local authority and installation code.
The use of the following gas connectors is recommended:
— ANS Z21.24 Appliance Connectors of Corrugated Metal
Tubing 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 authority
having jurisdiction. The state of Massachusetts requires that a
flexible appliance connector cannot exceed three feet in length.
Figure 1
Consult the current National Fuel Gas Code, ANSI Z223.1 CAN/
CGA-B149 (.1 or .2) installation code.
Installing a New Main Gas Cock
Each appliance should have its own manual gas cock.
In the state of Massachusetts the gas cock must be a T handle type.
A manual main gas cock should be located in the vicinity of the
unit. Where none exists, or where its size or location is not
adequate, contact your local authorized installer for installation
or relocation.
GAS SUPPLY
Compounds used on threaded joints of gas piping shall be
resistant to the action of liquefied petroleum gases. The gas lines
must be checked for leaks by the installer. This should be done
with a soap solution watching for bubbles on all exposed
connections, and if unexposed, a pressure test should be made.
Never use an exposed flame to check for leaks. Appliance
must be disconnected from piping at inlet of control valve and
pipe capped or plugged for pressure test. Never pressure test
with appliance connected; control valve will sustain damage!
A gas valve and ground joint union should be installed in the gas
line upstream of the gas control to aid in servicing. It is required
by the National Fuel Gas Code that a drip line be installed near the
gas inlet. This should consist of a vertical length of pipe tee
connected into the gas line that is capped on the bottom in which
condensation and foreign particles may collect.
Figure 2
Method of Installing a Tee Fitting Sediment Trap
Pressure Testing of the Gas Supply System
1. To check the inlet pressure to the gas valve, a 1/8" (3mm)
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
disconnected from the gas supply piping system during any
pressure testing of that system at test pressures in excess of
1/2 psig (3.5 kPa).
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 (3.5 kPa).
Attention! If one of the above procedures results in pressures in
excess of 1/2 psig (14" w.c.) (3.5 kPa) on the appliance gas valve,
it will result in a hazardous condition.
Checking Manifold Pressure
Both Propane and Natural gas valves have a built-in pressure
regulator in the gas valve. Natural gas models will have a
manifold pressure of approximately 4.0" w.c. (.996kPa) at the
valve outlet with the inlet pressure to the valve from a minimum
of 5.0" w.c. (1.245kPa) for the purpose of input adjustment to a
maximum of 10.5" w.c. (2.61kPa). Propane gas models will have
a manifold pressure approximately 10.0" w.c. (2.49kPa) at the
valve outlet with the inlet pressure to the valve from a minimum
of 11.0" w.c. (2.739kPa) for the purpose of input adjustment to a
maximum of 13.0" w.c. (3.237kPa).
A 1/8" (3mm) N.P.T. plugged tapping, accessible for test gauge
connection, is located on the outlet side of the gas control.
NPT NIPPLE
NPT NIPPLE