TABLE OF CONTENTS Process materials are normally contained within a pressure system. The main problem in loss prevention is the avoidance of loss of containment from this system. Thus, the First Report of the ACMH (Harvey, 1976) states: Containment is the very essence of the problem of control of dangerous materials, and therefore we regard the integrity of pressure systems as of the highest importance (paragraph 64).
The report continues: Scrutiny of incidents suggests that the outright failure of properly designed, constructed, operated and maintained pressure vessels is rare, perhaps because of the lessons learned over many years from steam boiler practice. It is pipework, valves, pumps, etc., which are vulnerable and much more prone to failure (paragraph 65).
Some of the principal features of pressure systems are briefly discussed in this chapter. It cannot be too strongly emphasized, however, that the discussion is limited to the background information necessary for the appreciation of the problems which occur in loss prevention and that many of the topics touched on, such as materials of construction, pressure vessels, piping, process machinery and overpressure protection, are complex matters which require specialist knowledge. The operation of pressure systems is at least as important as their design. This is considered in Chapter 6 on management systems and in Chapter 20 on plant operation. Selected references on pressure systems and components are given in Table 12.1 and on materials of construction for and corrosion in pressure systems in Table 12.2.
