Hello, Recently we had observed perforations/disintegration at about 5 - 6 locations on the shell of one of our above ground Fiber Glass Reinforced Tank in Caustic Service. The monolithic FRP tank is a small one i.e., 1m dia by 2 m height approx. Request to email me a copy of specification for Fiber Glass Reinforced Tank in Caustic Service. Also would look forward for hearing experiences of other forum members on similar problems. Regards, Chakradhar S email: chakradhars@yaoo.co.in

Chakradhar Krish had outlined correctly the problems in FRP tanks. Pin holes and degradation in FRP tanks or piping in DM water or Caustic service is well known. This is related to FRP filament winding technique and also the quality of resin, ( i.e, the ratio of filament winding to resin) used for bonding. Exposure during down time to sun light allows a faster degradation. This is common to FRP tanks and FRP piping used in DM plants and in Caustic storage or in Phos Acid service. Sometimes agitation in tanks lead to faster degradation at locations where bonding of resin with FRP (flimaent wound type design) is poor or exposure to UV light (sun light). FRP Specification needs vary with each fabricator and the type of filament winding design. Generally a hand trowelled design - filament to resin ratio - may not give equal application of resin coverage at all places. Such local areas are weak spots for faster degradation and pin hole leak development due to resin application not good and also exposure to UV light for a long time. ASTM specification is also available. ASME code also gives guideline specification for FRP storage vessels under pressure conditions. Keeping the tank to 60% -80% fill always with caustic solution may solve problems at the tank sides and tank bottom. Still vapor load at the load and direct exposure may give problems of pin hole degradation at the top and at the vapor space of tanks and piping. Trust this will help you C.V.Srinivasan Nishi Engineers Pvt Ltd India Dec 2, 2006 E-mail: nishi@vsnl.com >Hello, > >Recently we had observed perforations/disintegration at >about 5 - 6 locations on the shell of one of our above >ground Fiber Glass Reinforced Tank in Caustic Service. The >monolithic FRP tank is a small one i.e., 1m dia by 2 m >height approx. > > >Request to email me a copy of specification for Fiber Glass >Reinforced Tank in Caustic Service. > >Also would look forward for hearing experiences of other >forum members on similar problems. > >Regards, > >Chakradhar S >email: chakradhars@yaoo.co.in