TABLE OF CONTENTS As chemical manufacturers, we must continually modify our facilities to survive in our dynamic industry. Without the appropriate changes, our clever competition or our governmental regulators will surely drive us out of business. The goal of these modifications may be to increase production, to compensate for unavailable equipment, to add storage capacity, to improve yields, to reduce costs, to enhance safety, or to reduce pollution potentials. The means to achieve these goals may be changes in piping or equipment, new operating procedures, new operating conditions, changes in material of construction, as well as the process chemical changes in feedstocks, catalyst, fuels, or their method of delivery.
The first series of modifications featured in this chapter were all motivated by "Good Intentions." In spite of creative ideas and considerable effort, these modifications failed because no one took the time to examine and expose their weaknesses. These undetected weaknesses caused undesired side effects.
In late 1991, a tank truck catastrophically collapsed as it was unloading a product from a nearby plant (see Figure 2-1). The 6,300 gallon (24,000 L) tank on the trailer, which had a name-plate design pressure of 30 psig (2.0 bar), appeared to be very well maintained and in excellent condition prior to the accident. [1] The assistant trucking terminal manager described the ruined equipment as the worst tank truck collapse that he had witnessed in his 25 years of trucking.
