A 12 inch (305mm) diameter FRP piping section containing Furan resin disintegrated after four years of service in a vapor relief system. External inspection of the flare stack conducted just three months earlier revealed no obvious problems. Also, during the ensuring period, there were no
upsets in temperature, pressure or process operations. A detailed investigation determined that excessive mechanical stresses at the unsupported 45 degree elbow joints led to strain corrosion and
subsequent crumbling of the FRP material. The remainder of the piping and flanges were in good condition. Steps necessaty to minimize future problems and the need for industry wide design, inspection and maintenance guidelines are discussed.
Keywords: FRP, Furan, strain corrosion, suppotis, flare stack, inspection, Furfuryl alchohol, Fiberglass reinforced plastics