Electric immersion heaters are commonly used in tank and pressure vessel heating applications, where there is a requirement to maintain liquid temperature to a certain controlled set point. Typical applications include: antifreeze protection on refueling water storage tanks, oil tanks, fuel-oil tanks, diesel tanks, water tanks, vaporizing vessels and others. Immersion heaters are designed and manufactured in accordance with ASME Section III, Class 1, 2 or 3 and stamped NPT according to code requirements. Immersion heaters also are designed and manufactured under ASME Section VIII, Div. 1 for non nuclear code applications.