SPECIFICATION FOR DOMESTIC WATER HEATERS
Power Combustion, Low Nox, Gas-Fired Water Heaters with Polymer-Lined Storage Tanks
Furnish and install MAXIM power combustion gas water heater(s) as manufactured by PVI Industries, LLC
of Fort Worth, Texas. Supply quantities and model numbers as indicated on the plumbing schedule.
Gas and Electrical Consumption
The water heater will operate at a minimum of 82% thermal efficiency when tested by an independent laboratory 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. All tank
connections will be non-ferrous. 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.
Tank Lining
The lining will:
be applied only after the tank is completely fabricated and all welding is completed.
consist of multiple applications of high-temperature fluoropolymer.
be third-party tested to comply with NSF 61 standard.
be continuous and nonporous with no interruptions or discontinuities.
require no sacrificial anode rods for protection.
Burner and Venting
Combustion will be provided by a forced-draft power burner with a gas train meeting the following agency
requirement for the input specified:
___ UL (standard)
___ FM
___ IRI
___ Other ______________________
Burner and heating section will be certified to operate with NOx emissions not to exceed 30 ppm corrected to 3% O2
(at or above 400,000 Btu) and 55 ppm corrected to 3% O2 or 40 nanograms per joule (below 400,000 Btu). Water
heater will be a category I, non-condensing appliance. It will be UL listed for use with non-pressurized, type B venting
material.
(continued)
PV 6314 4/04
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