T-5 Amtrol THERM-X-SPAN Expansion Tank, 2.0 Gallon The Amtrol THERM-X-SPAN T-5 Expansion Tank has a steel shell, plastic liner, and rubber diaphragm with a brass system connection. The maximum operating temperature is 200ºF and the maximum working pressure is 150 PSIG. Unit comes with a 40 PSIG factory precharge. Tank Volume (Gallons) - 2.0Max. Accept Factor - 0.45System Connection (Inches) - 3/4Height (Inches) - 12-5/8Diameter (Inches) - 8Shipping Weight (lbs.) - 5Temperature = 200°F. Maximum Working Pressure = 150 PSIGFactory Precharge = 40 PSIG