V. Gas Piping
WARNING
Failure to properly pipe gas supply to boiler may result in improper operation and damage to the boiler or structure. Always assure gas piping is absolutely leak free and of the proper size and type for the connected load.
An additional gas pressure regulator may be needed. Consult gas supplier.
A.Size gas Piping. Design system to provide adequate gas supply to boiler. Consider these factors:
1.Allowable pressure drop from point of delivery to boiler. Maximum allowable system pressure is ½ psig. Actual point of delivery pressure may be less; contact gas supplier for additional information. Minimum allowable gas valve inlet pressure is indicated on rating label.
2.Maximum gas demand. Table 5 lists boiler input rate. Also consider existing and expected future gas utilization equipment (i.e. water heater, cooking equipment).
3.Length of piping and number of fittings. Refer to
Table 6 for maximum capacity of Schedule 40 pipe.
Table 7 lists equivalent length for standard fittings.
Table 5: Rated Input
Boiler | Rated Capacity | Gas | |
(cubic feet per hour) | Connection | ||
Model | Natural | LP / Propane | Size |
| |||
805H | 252 | 100.8 | 1 |
806H | 315 | 126 | 1 |
807H | 374 | 149.6 | 1 |
808H | 433 | 173.2 | 1 |
809H | 491 | 196.4 | 1 |
810H | 550 | 220 | 1 |
4.Specific gravity of gas. Gas piping systems for gas with a specific gravity of 0.70 or less can be sized directly from Table 6, unless authority having jurisdiction specifies a gravity factor be applied. For specific gravity greater than 0.70, apply gravity factor from Table 8. If exact specific gravity is not shown choose next higher value.
For materials or conditions other than those listed above, refer to the National Fuel Gas Code, NFPA 54/ANSI Z223.1 and/or CAN/CSA B149.1 Installation Codes, or size system using standard engineering methods acceptable to authority having jurisdiction.
WARNING
Failure to use proper thread compounds on all gas connectors may result in leaks of flammable gas.
WARNING
Gas supply to boiler and system must be absolutely shut off prior to installing or servicing boiler gas piping.
B.Connect boiler gas valve to gas supply system.
1.Use methods and materials in accordance with local plumbing codes and requirements of gas supplier. In absence of such requirements, follow the National Fuel Gas Code, NFPA 54/ANSI Z223.1 and/or CAN/CSA B149.1 Installation Codes.
2.Use thread (joint) compound (pipe dope) resistant to action of liquefied petroleum gas.
3.Install sediment trap,
4.All above ground gas piping upstream from manual gas valve must be electrically continuous and bonded to a grounding electrode. Do not use gas piping as a grounding electrode. Refer to the National Electrical Code, ANSI/NFPA 70 and/or CSA C22.1 Electrical Code.
NOTICE
USA boilers built for installation at altitudes greater than 2,000 feet above sea level have been specially orificed to reduce gas input rate 4 percent per 1,000 feet above sea level per the National Fuel Gas Code, NFPA 54/ANSI Z223.1, Section 8.1.2 and Appendix F. Canadian boilers’ orifice sizing is indicated on the rating label. High altitude boiler models are identifiable by the model number’s tenth digit on the rating label. (4=2000’ - 4500’, 5= 2000’ - 5000’)
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