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SPECIFICATION FOR DOMESTIC WATER HEATERS
Condensing, Low NOx, Gas-Fired Water Heaters with Nickel-Plated Storage Tanks
Furnish and install POWER VT condensing gas water heater(s) as manufactured by PVI Industries, LLC
of Fort Worth, Texas. Supply in quantities and model numbers as indicated on the plumbing schedule.
Emissions
NOx emissions will not exceed 30 ppm when corrected to 3% O2 (for inputs greater than 399,000 Btu).
NOx emissions will not exceed 55 ppm when corrected to 3% O2 (for 399,000 Btu input). These levels will be
certified by independent agency.
Gas and Electrical Consumption
The water heater will operate at a minimum of 94% thermal efficiency when tested to ANSI Z21.10.3. The water
heater will comply with paragraph 7.2.4.4, the thermal efficiency, the standby loss, and all other requirements of
ASHRAE 90.1-1999.
Pressure Vessel and Heating Surfaces
The water heater will be a vertical fire tube design that is constructed and stamped in accordance with Section IV,
Part HLW of the ASME code. Both the storage and heating sections of the water heater will be National Board
Registered for a working pressure of 150 psi and will be pressure tested at 1-1/2 times working pressure. The fireside of
the heating surfaces will be of boiler-grade steel. The waterside of the heating tubes will be sealed in copper. The
heating tubes will be rolled, beaded, and seal welded into the tube sheets. The combustion side of the tube sheet will be
insulated by a layer of ceramic fiber that will protect the tube sheet from both thermal stresses and failure that can result
from the accumulation of scale and precipitants.
Lining
The tank will be a plated with electroless nickel (EN). Plating will occur after the pressure vessel is completely
fabricated and all welding is completed. The EN plating will be a high-phosphorus (10%) and nonporous composition
suitable for submersion service (ASTM B733 standard may be used as a guideline). The finished lining will not require
sacrificial anode rods. For additional protection against galvanic corrosion, which may occur within the potable water
system, the EN plating may have a high-dielectric-strength polymer overcoat.
Burner and Venting
Combustion will be provided by an induced-draft power burner with a gas train meeting the following agency
requirement for the input specified:
___ UL (standard)
___ FM
___ IRI
___ Other ______________________
Water heater will be a category IV, condensing appliance, UL listed for use with CPVC vent or AL 29-4C stainless
steel vent. Burner will be configured to accept ____ room air _____ direct inlet combustion air. Water heater will operate
with a minimum gas pressure of 4-½ inches water column.
(continued)
PV 6319 4/04
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