GAS SUPPLY
Recommended Gas Pipe Diameter
| Pipe Length | Schedule 40 Pipe | Tubing, Type L | ||
| (Feet) | Inside Diameter | Outside Diameter | ||
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| Nat. | L.P. | Nat. | L.P. |
| 1/2" | 3/8" | 1/2" | 3/8" | |
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| 1.3 cm | 1.0 cm | 1.3 cm | 1.0 cm |
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| 1/2" | 1/2" | 5/8" | 1/2" | |
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| 1.3 cm | 1.3 cm | 1.6 cm | 1.3 cm |
| 1/2" | 1/2" | 3/4" | 1/2" | |
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| 1.3 cm | 1.3 cm | 1.9 cm | 1.3 cm |
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| 3/4" | 1/2" | 7/8" | 3/4" | |
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| 1.9 cm | 1.3 cm | 2.2 cm | 1.9 cm |
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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
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.
NPT NIPPLE
NPT NIPPLE 
Figure 1
Consult the current National Fuel Gas Code, ANSI Z223.1 CAN/
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.
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
A 1/8" (3mm) N.P.T. plugged tapping, accessible for test gauge connection, is located on the outlet side of the gas control.
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