Appliance details
2.8Gas piping & connections 
Before connecting the gas supply, check the rating plate on the right side of the heater to be sure that the heater is rated for the same gas to which it will be connected.
In the United States: The installation must conform with local codes or, in the absence of local codes, the National Fuel Gas Code ANSI Z223.1/NFPA 54.
In Canada: The Installation should conform with CGA B149 INSTALLATION CODES and/or local installation codes.
GAS LINE SIZING
The gas supply piping should be sized according to the applicable plumbing code for a maximum draw of 175,000 BTUH. Measure the length of gas supply line and use the tables in Fig. 12 or the gas line manufactures sizing tables to determine the pipe diameter necessary to accommodate the BTU demand of the unit. If there are more gas drawing appliances on the line, size the gas line according to the total maximum amount of BTU draw for all appliances.
Note: Under sizing the gas line may result in diminished output and improper operation. See chapter 2.9 for the procedure to confirm gas pressure.
Inlet gas particle screen Gas piping
Fig. 11
BInstall a manual gas shut off valve, on the gas supply line.
BThe use of a union when connecting gas pipe to the gas inlet connection is important, this will facilitate any necessary servicing and cleaning of the inlet gas particle screen.
BThe minimum diameter required for any appliance connector used is ¾”.
BNational Fuel Gas Code requires that a sediment trap (drip leg) be installed on gas appliances not so equipped. The drip leg must be accessible and not subject to freezing conditions. Install in accordance with the recommendations of the serving gas supplier.
Warning: The heater must be isolated from the gas supply piping system during any pressure testing of that system at test pressures equal to or more than 0.5 psig.
The water heater must not be piped with gas supply pressures in excess of 0.5 psig. If overpressure has occurred, such as through improper testing of the gas lines or malfunction of the supply system, the gas valve must be checked for safe operation.
When connections are made, check for gas leaks at all joints. Apply some gas leak detection solution to all gas fittings. Bubbles are a sign of a leak. A Combustible Gas Detector may also be used to detect for leaks.
Danger: If you have a leak, shut off the gas. Tighten appropriate fittings to stop leak. Turn the gas on and check again with a gas leak detection solution. Never test for gas leaks using a match or flame.
10 | 6 720 607 440 |
