Fiberglass acid tank

The fiberglass acid tank was out-of-service because it had just been washed. If the level in the acid tank was ever overfilled, the 4-inch (10 cm) overflow line would relieve into the adjacent chemical collection sewer. The sewer was scheduled for maintenance. As a precaution to protect the individuals assigned to repair the chemical collection sewer, an operations supervisor authorized the maintenance crew to blind the 4-inch (10 cm) overflow line. The operations supervisor provided instructions to the operators to limit the liquid level within the acid tank to a well-defined maximum. 

The fiberglass acid tank was out-of-service because it had just been washed. If the level in the acid tank was ever overfilled, the 4-inch (10 cm) overflow line would relieve into the adjacent chemical collection sewer. The sewer was scheduled for maintenance. 

Figure 7.16 A large fiberglass acid tank fails due to blinded vent line and blinded overflow line.

Figure 7.17 An aerial view of the large fiberglass acid tank failure at the floor.

An 80 m3 tank fiberglass-reinforced plastic acid tank was blown apart at the base as the result of overpressure. The vent had been slip-plated so the tank could be entered for inspection. The steel slip-plate was covered with a corrosion-resistant sheet of polytetrafluoroethylene. Afterward, when the slip-plate was removed, the sheet was left behind. This did not matter at the time, as the tank was also vented through an oveiflow line,... 

In this case, a high-resolution scanner is used to monitor the electrolytic cells in the tankhouse of a zinc refinery, where acres of acid-filled tanks contain pure metal anode starter plates onto which the refined metal is deposited electrolytically from unrefined cathodes in close proximity. When contact short circuits occur between electrode pairs in the tankhouse, metal production between the shorted pairs is halted, excessive current flows, and power is wasted. An IR scanner, mounted in a fiberglass environmental enclosure on the same overhead crane used to deposit and remove electrodes from the acid bath, maps the process and pinpoints the shorts, allowing service personnel to clear them with minimal exposure to toxic acid fumes. The shorts appear as hot spots on the computer-monitored thermal map. 

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