Typical Specification for Niles Steel Tank Hot Water Storage Tanks



Provide a vertical (horizontal) storage tank per the size and capacities as indicated.  Tank and insulation to be produced by NILES STEEL TANK.

A.  The storage tank shall be a Niles Steel Tank, Model _________ with a diameter of ___ and having a true volume capacity of ____ US gallons and equipped with a steel skirt or (steel saddles on horizontal tanks) and constructed of carbon steel in accordance with standard ASME Boiler and Pressure Vessel Code requirements.  The storage tank will be stamped and registered with the National Board of Boiler and Pressure Vessel Inspectors.  Tanks shall be internally lined with ULTONIUM premium enamel coating per ASME HLW Code procedures at a finished thickness of__ mils (10 ~12 mils = single coat, 20 ~ 24 mils = double coat).  The storage tank will be hydrostatically tested for 125 PSI (150 PSI)  working pressure.  Tanks shall have two (2) lifting lugs, four (3) 3” npt fittings, one (1) 1” drain, one (1) 1 ¼” T&P Relief fitting, and two (2) npt fittings for aqua-stats.  Tanks shall be externally prime coated with red oxide primer.

B. Tanks shall be furnished with the Niles Electric Anode System designed specifically for the Niles Ultonium lined storage tanks.  The electric anode system will provide cathode protection through non-consumable titanium rods for maximum protection.  The Niles Electric Anode System is to be a maintenance free system and requires no bi-annual anode inspection. (NOTE – The NST electric Anode system is available on NST tanks up to 860 gallons, larger sizes need to be properly sized)

C.  Ultonium Glass Lining to be applied in ambient room temperatures to a wet thickness of 24 mils to a sandblasted, white metal surface then cured in a drying oven at 400F degrees.  All threaded fittings are to be wired brushed clean before the firing process.  Firing of the vessel is to be done at 1530F degrees for a period of time which will allow the Ultonium to liquefy and bond to the steel substrate.

D.  Double Ultonium Glass Lining – The Niles Steel Tank water storage tank(s) are (is) to be manufactured with a double Ultonium Glass lining process.  The storage tanks will have a finished glass thickness of 20 to 24 mils of Ultonium glass and carry a 10 year warranty.  The tank(s) will be cooled and lightly sandblasted between coats to ensure proper adhesion.

E.  Insulation shall be Niles Steel Tank spayed-on rigid polyurethane insulation with acrylic topcoat which exceeds ASHREA 90.1b requirements.  Niles Steel Tank spray foam insulation to have a class I foam rating with less than a 25-flame spread rating suitable for boiler room applications.  Insulation shall be applied at the factory at room temperature directly to the tank in a 2 step application process with 2.25” of foam added per application with a total insulation value to be R-16.  The acrylic top-coat is to be applied in a 2 step application process, applying approximately 12.5 mils of material per coat and allowed to dry between applications.

F.  Jacketed and insulated tanks are to have an open cell 2 part rigid insulation sprayed into a 2” cavity surrounding the storage tank.  The foam insulation to be Niles Steel Tank foam insulation which meets ASHREA 90.1b requirements with an insulation value of R-12.5.  The steel jacket is to be 24 gauge steel, painted on both sides with a baked-on enamel coating.

G.  The storage tank is to be equipped with a Niles Diverter Tube.  The diverter tube is to be constructed with heavy gauge stainless steel and designed with an angled plate opening along the bottom of the tube.  The angled plate opening will have a 30% more combined volume than the sparge tube which will allow the incoming water to slow and gently enter the tank maintaining temperature stratification.  The Niles Diverter Tube will allow 85% of the tanks usable hot water to be drawn without a noticeable temperature drop.

H.  Tanks shall have a minimum 5-year warranty. (Tanks shall have a 10-year warranty with the Double Ultonium glass option.)