TF and TFR immersion tube burner series are prewired, prepiped burner packages used to heat liquid process tanks. Developed for small-bore applications, TFR burners maximize the heat release in small 2.5 - 8 in. (65-200 mm) diameter tubes having length-to-diameter ratios up to 150:1. The series can be used with natural and LP gases, and are available in eight sizes ranging having thermal capacities from 240,000 to 2,600,000 Btu/hr. TF burners have standard nozzle mix burner heads for use with conventional size firing tubes having diameters up to 12 in. (300 mm) and length-to-diameter ratios up to 80:1. The burners can be used with natural or LP gases and are available in ten sizes having thermal capacities from 170,000 to 3,300,000 Btu/hr.