A book in the Centennial College Press Gas Fitter Series This text is designed to provide the basic principles of operation and application of industrial and commercial gas burner systems. This book is appropriate for students enrolled in courses in industrial and commercial gas fitting or journeymen in the field preparing for provincial certification as commercial and industrial gas fitters. The intent of the text is to develop within the student an understanding and appreciation of those principles and applications. The student is guided through the principles of flame detection, flame safeguard control, temperature control and firing rate control. The text outlines and devel-ops the application of non programming and programming flame safeguard controls, valve train assemblies, limit controls and interlocks, types of boilers and air heating units and the requirements for burner installations. Assign -ments at the end of each chapter are intended to get the student involved. They can be used to stimulate classroom discussion or to provide a series of useful questions for hand-in written assignments. Although high input systems up to 50,000,000 Htuh (14,650kW) are mentioned in chapter 10, Valve Train Assemblies Part III, the main scope of the text is on burner systems between 400,000 Btuh (120kW) and 10,000,000 Btuh (2930 kW). This is the general range of equipment to which the commercial and industrial gas fitter is exposed. This book should prove beneficial at various levels; it is appropriate for community college day program students, community college night school students taking courses in commercial and industrial gas fitting or journeymen in the field, preparing for provincial certification as commercial and industrial gas fitters. However, the text presupposes that the student has an adequate background in the fundamentals of natural gas utilization in such areas as properties of natural gas, combustion and flue gas analysis, gas meters and regulators, gas piping, gas venting, the atmospheric burner, and residential and light commercial gas controls. The text, therefore, is a continuation of Fundamentals of Gas Utilization, also published by Centennial College Press, in which the above fundamentals are covered. PUBLISHER'S NOTE: This book was originally published in 1985. While every care has been taken in the reprinting of this text, it should be noted that in the original text layout, many diagrams and illustrations are reproduced at a small size, although all the labels and captions are legible. Furthermore, in some cases the diagrams and figures have been reproduced from scans of the originals. While the appearance of the book is comparable to the original edition, and the information included in the book remains invaluable, we do want readers to know that the design specifications of this text reflect the standards of 35 years ago rather than those of today.