Feldmeier Stainless Steel Triple Tube Heat Exchanger- 12 Tubes. Tube thickness: 0.067 in. Outer tube: 2.5 in. diameter x 222 in. L, heating surface area: 12.12 sq. ft. Approximate liquid capacity: 4.7 gallons. Intermediate tube: 2.0 in. diameter x 236 in. L, heating surface area: 10.30 sq. ft. Approximate liquid capacity: 3 gallons. Inner tube: 1.5 in. diameter x 236 in. L, heating surface area: 7.72 sq. ft. Approximate liquid capacity: 1.8 gallons. Concentrically mounted tubes. In actual process, the heating or cooling medium travels in one direction through the inner tube and through the annular space between the intermediate and outer tubes. The product flows in the opposite direction through the annular space between the inner tube and the intermediate tube. This produces counter flow action. Substantial heat exchange efficiency results from this counter flow. Its (3) columns support the weight of the tubes and are used to attach unit to floor or base structure. Inlets/outlets: (4) 3 in. 'S' line fittings, with (2) valves. Overall dimensions: 21 ft. L x 2 ft. 7in. W x 3 ft. 5 in. H.