Hydronic Expansion Tank; Type In-Line, Vertical; Inlet/Outlet Connection 1-1/4 Inch Female Threaded x 1-1/4 Inch Female Threaded; Tank Material High Strength Steel; Temperature Rating 240 Deg F; Pressure Rating 100 PSIG; Tank Capacity 4.4 Gallon; Tank Warranty 7 Year; Diaphragm Type Heavy Duty Butyl/EPDM; Air Charge Type Factory Pre-Charged; Air Charge Capacity 12 PSIG; Inclusions/Features Steel Shell, Projection Welded Air Stem; Application Hydronic Heating System, Boiler; Applicable Standard ISO 9001