A small scab ultra high temperature (UHT) sterilizer suitable for rural tropical cooperatives was designed and tested. An indirect tubular type UHT sterilizer is better suited to small scale operation and low investment cost. A triple tube heat exchanger (TTHE) was designed for heating milk from 95 to 145 degrees C in the annulus sf the triple tube using steam in the innermost and the outermost tubes. The holding section was designed to provide 4.3 s residence time to reduce B. Stearothermophilus by 8 log cycles. The cooling section was designed to cool milk from 145 to 95 degrees C by using water. An iterative procedure was followed to develop software to handle design calculations. Heating holding, and cooling sections were found to be of 3, 0.6 and 3.1 m length. The set up was tested with milk for determination of heat transfer coefficients.