Burnham PVG manual Gas Piping, Failure to properly pipe gas supply to boiler may, Gas Ratings

V. Gas Piping

					Table 7 for maximum capacity of Schedule 40 pipe.
		WARNING
					Table 8 lists equivalent pipe length for standard
					fittings.
Failure to properly pipe gas supply to boiler may
					4. Corrections for the specific gravity of natural gas
result in improper operation and damage to the
boiler or structure. Always assure gas piping is					can be found in Table 6.
absolutely leak free and of the proper size and
type for the connected load.					Table 6: Specific Gravity Correction Factors for
An additional gas pressure regulator may be
					Natural Gas
needed. Consult gas supplier.
					Specific	Correction	Specific	Correction
A. Size gas piping. Design system to provide adequate gas
					Gravity	Factor	Gravity	Factor
supply to boiler. Consider these factors:					---	---	0.85	0.81
1. Allowable pressure drop from point of delivery to					---	---	0.90	0.82
boiler. Maximum allowable system pressure is ½					0.60	1.00	1.00	0.78
psig. Actual point of delivery pressure may be less;
					0.65	0.96	1.10	0.74
contact gas supplier for additional information.
					0.70	0.93	1.20	0.71
Minimum gas valve inlet pressure is stamped on
the rating label located in the boiler’s vestibule					0.75	0.90	1.30	0.68
compartment.					0.80	0.87	1.40	0.66
2. Maximum gas demand. Refer to the boiler’s input as
printed on its rating label. Also consider existing and					For materials or conditions other than those listed
expected future gas utilization equipment (i.e. water
heater, cooking equipment).					above, refer to National Fuel Gas Code, NFPA54/ANSI
3. Length of piping and number of fittings. Refer to					Z223.1, or size system using standard engineering
					methods acceptable to authority having jurisdiction.
	Table 5: Gas Ratings
	Boiler	Natural/LP	Minimum Natural	Minimum LP		Natural	LP
	Model	Maximum	Gas Pressure	Gas Pressure		Manifold	Manifold
	Number	Gas Pressure	(in. w.c.)	(in. w.c.)		Pressure	Pressure
		(in. w.c.)	Inlet to Gas Valve	Inlet to Gas Valve		(in. w.c.)	(in. w.c.)
	PVG-3
	PVG-4
	PVG-5
	PVG-6	14	4.5	11.5		3.5	10.5
	PVG-7
	PVG-8
	PVG-9

NOTICE

PVG boilers built for altitudes greater than 4,999 feet above sea level need to be specially orificed to adjust for changes in atmospheric conditions. The PVG boiler “H” Model has been certified to operate in atmospheric conditions from 5,000 to 10,000 feet above sea level. Input is derated by 10% for applications at 5,000 feet above sea level, and 20% for applications at 10,000 feet above sea levels. Derate is based on 2% reduction per 1000 feet.

The PVG boiler is available in two (2) altitude Models: The “S” Model 0 to 4,999 feet above sea level, and the “H” Model 5,000 to 10,000 feet above sea level.

For applications above 10,000 feet, consult the manufacturer.

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