FRP cooling tower profiles for wet and chlorinated service

A cooling tower is close to a worst-case environment for coated steel: the structure sits in saturated air at elevated temperature, gets sprayed with chlorinated and chemically dosed water, dries out, and is wetted again — thousands of cycles a year. Galvanizing sacrifices itself, coatings blister at cut edges and bolt holes, and every recoating cycle means a plant outage with confined-space access. Pultruded fiberglass removes the failure mechanism instead of slowing it down: the glass-fiber laminate is immune to electrochemical corrosion, and a vinyl ester matrix resists the chlorides, biocides, and pH swings of open recirculating water.

The industry recognized this decades ago — fiberglass pultrusions are now the default structural material for new field-erected towers, and the Cooling Technology Institute maintains a dedicated specification (CTI STD-137) for pultruded structural products used in them. Typical member mapping in a tower frame: I-beams and channels for columns, girts, and fan-deck framing; square tubes for diagonal bracing and casing support; angles for louver frames and connection cleats; and thin-wall custom sections for louvers and drift-eliminator supports. All of these come from the same standard families listed in our size catalog, with published weights per meter.

For replacement programs, the practical route is to match the existing steel member geometry at equal stiffness rather than equal depth — fiberglass runs at roughly a quarter of the weight of the steel it replaces, which usually means the old crane and access plan can be downsized or eliminated. Send the existing framing drawings and water-chemistry report with your RFQ; we return a member-by-member substitution list with section sizes, resin recommendation, and hardware notes, priced per meter.