Recommended Gas Pipe Diameter
Schedule 40 Pipe
Pipe
Inside Diameter
Length
Natural
0-10 feet
1/2"
0-3 meters
12.7mm
10-40 feet
1/2"
4-12 meters
12.7mm
40-100 feet
1/2"
13-30 meters
12.7mm
100-150 feet
3/4"
31-46 meters
19mm
NOTICE: Never use plastic pipe. Check to confirm whether your
local codes allow copper tubing or galvanized.
NOTICE: 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:
— ANSI Z21.24 Appliance Connectors of Corrugated Metal Tubing
and Fittings
— ANSI 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 Commonwealth of Massachusetts requires
that a flexible appliance connector cannot exceed three feet in length.
GAS SUPPLY
TEE HANDLE
FLEX TUBING
FLARE SHUT OFF VALVE
CLOSE NIPPLE
TEE HANDLE
SHUT OFF VALVE
NPT GAS SUPPLY
Consult the current National Fuel Gas Code, ANSI Z223.1 CAN/
CGA-B149 (.1 or .2) installation code.
Installing a New Main Gas Shut-Off
Each appliance should have its own manual gas shut-off.
A manual main gas shut-off 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.
Compounds used on threaded joints of gas piping shall be resistant
to the action of liquefied petroleum gases. The gas lines must be
38151-4-0320
GAS SUPPLY
Tubing, Type L
Outside Diameter
Propane
Natural
Propane
3/8"
1/2"
9.5mm
12.7mm
1/2"
5/8"
12.7mm
15.9mm
12.7mm
1/2"
3/4"
12.7mm
19mm
12.7mm
1/2"
7/8"
12.7mm
22.2mm
NPT NIPPLE
FLARE FITTING
NPT NIPPLE
NPT UNION
Figure 1
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
3/8"
capped or plugged for pressure test. Never pressure test with
9.5mm
appliance connected; control valve will sustain damage!
1/2"
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
1/2"
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
3/4"
and foreign particles may collect.
19mm
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.
Figure 2
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