When used in tandem with Rheem commercial water heating equipment, these storage tanks provide the flexibility needed for many commercial applications. Installed individually, or manifolded, these storage tanks can provide 80% draw capability without an appreciable temperature decrease in single temperature applications. Long Life Tank Design Unique steel formulation with high temperature porcelain enamel maximizes corrosion resistance and results in a superior tank design. Heavy duty magnesium anode rod(s) are installed for longer tank life. Efficient Design Rigid 2" polyurethane foam insulation provides superior insulating qualities and results in reduced operating costs. Our patented process of injecting foam into the insulating cavity adds additional durability and toughness to the baked enamel steel outer jacket. Tank Openings Circulating line connections and hot outlet are 2" NPT on the ST80 and ST120 and 2-1/2" NPT on the ST175. Other openings are provided for relief valve and temperature control. All commercial storage tank models are certified to ASME boiler and pressure vessel code standards. Warranty 5-Year limited tank warranty against tank leaks.