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This chapter covers ASME Boiler and Pressure Vessel Code Section VII, which presents guidelines for safe, reliable operation as well as avoiding unsafe conditions in power boilers. The guidelines apply to power boilers that produce steam for external use at a pressure exceeding 15 psig from the application of heat, which come from the combustion of fuels, from various hot waste gases, or from the application of electrical energy. The bulk of this chapter is devoted to the discussion on Subsection 1 of Section VII, which contains information about industrial, gas- or oil-fired, watertube boilers. Subsection 1 introduces the fundamentals of watertube boilers, the principles of boiler operation, the associated auxiliaries, and appurtenances required by ASME Code Section I. It also introduces the necessary instrumentation, the examinations to be performed by boiler operators and staff, and the requirements for repairs, alterations, and maintenance. Subsection 2 presents an overview of the control of chemical conditions within steam boilers. It provides information relating to internal cleaning and laying-up of boilers, internal corrosion due to deposits within boiler tubes, and corrosion cracking. The discussion covers the types of water treatment problems within boilers, and how each problem may be recognized and corrected so as to prevent boiler failures. Subsection 3 deals with firetube, electric, and utility boilers and Subsection 4 includes all information pertaining to coal-fired and other solid-fuel-fired boilers. Articles in Subsection 4 describe the types of ash and their removal and contain short generic lists of maintenance checks for these boilers. Subsection 5 is a glossary of the terms that may be used when referring to a power boiler and its associated facilities. Section VII is a practical boiler book, a good review for experienced personnel and a good teaching aid for less-experienced personnel. History The original author of this chapter was Edmund W. K. Chang. The second and third editions were updated by Edmund W. K. Chang and Geoffrey M. Halley. The fourth edition was updated by James T. Pillow. The fifth edition was completely revised by William L. Lowry. Barrie Mollitor updated this chapter for the current online edition. |
