A primary neutralization tank made of FRP (fiberglass reinforced plastic) was 30 years old
and leaking from somewhere at the bottom. The vessel was open top with an 18 foot (5.5 m)
diameter and 20.5 foot (6.25 m) straight shell. The vessel was surrounded by a metal
structure, which supports the vessel's agitator, as well as, housing covering equipment used
for the primary and secondary neutralization vessels. The vessel had to be replaced, but since
the vessel was the first one to neutralize the waste stream, it could not be out of service for too
long. The cost of removing the metal structure and replacing it would be very costly and
require additional time. The question was how could the vessel be replaced without removing
the metal structure?
Large FRP vessels have been fabricated in separate sections at fabricator shops, and sent to
assembly sites for several decades. This paper describes the methods used to remove the old
vessel and install and assemble the new vessel.
Keywords: FRP, fiberglass reinforced plastic, GRP, glass reinforced plastic, RTP, reinforced
thermoset plastic, field fabricated, field assembled, waste water tank, FRP hot weld.