Fiberglass Grating Chemical Resistance by Resin and Exposure

Start with the process fluid and the maintenance routine. A walkway above a vessel, a drain cover exposed during washdown and a panel in continuous contact with liquid need separate descriptions. Record what reaches the grating, how often it happens and how quickly the surface is cleaned. Include both normal operation and foreseeable shutdown or cleaning conditions.

• Chemical identity: provide the chemical name, concentration range and safety data sheet. For a proprietary cleaner or mixed process stream, include its composition for technical review.
• Temperature: state normal and peak contact temperatures, the duration of peaks and any cleaning cycle. Distinguish the liquid temperature from the surrounding air temperature.
• Contact pattern: identify continuous contact, frequent splashes or occasional spills. Describe pooling, drainage and the cleanup procedure.
• Other conditions: include outdoor exposure, abrasion, loading, support layout and any requirements for food contact, electrical behavior or fire performance.

Give each exposure area a drawing reference. A platform above a treatment tank and the dosing-area drain cover may encounter different liquids, temperatures and cleaning routines. Keep those locations separate in the resin schedule even when both belong to the same wastewater project.

The chemical chart compares vinyl ester, isophthalic and general-purpose polyester. Ratings differ by row, so do not assume a resin is suitable for every chemical because it performs well in another service. Ask the supplier to identify which chart column applies to the exact resin system offered. The catalog’s “food grade” description also does not establish approval for a particular food-contact application; specify the documentation your project requires.

After screening the resin, use the molded and pultruded grating comparison to review construction and load direction. Resin selection and panel selection are separate decisions: an acceptable chemical rating does not determine the mesh, depth, span or support arrangement.

Match the substance and concentration first, then read the temperature and the rating for the proposed resin. “Continuous” is a different category from “Splash and spill.” An “Occasional splash” rating assumes infrequent contact followed by prompt cleanup; do not use that row as approval for immersion or liquid left standing on the panel.

Separate rows matter. The catalog lists different concentrations of ethanol, ammonium bicarbonate and sodium hydroxide, with changes in the resin ratings. Check the complete operating range instead of selecting the most favorable entry. If the chemical, concentration, mixture or temperature is outside the listed conditions, request a documented review rather than extending a nearby rating.

The sodium-hydroxide rows below show why the chemical name alone is insufficient. They are the catalog entries, not recommended operating conditions. Read across the row matching the concentration, retain its temperature condition, and then check the contact category for the proposed resin.

1. In the lower-concentration row, the vinyl-ester cell is rated “Occasional splash,” which requires prompt cleanup. It does not support continuous contact or frequent washdown.
2. The higher-concentration row rates all three resin columns “Not recommended.” A favorable result at a lower concentration cannot be carried into that row.
3. For a dosing area, record both the diluted working solution and a possible concentrate spill. If neither printed row matches the proposed conditions, request a documented material review rather than interpolating between ratings.

The complete chart below reproduces the chemical environments recorded in Strongrate’s catalog. It is general information derived from resin makers’ data, not a test report for your installation or a prediction of service life. Preserve the selected row and all its conditions in the material review.

Check the selected grating model against the load and deflection tables. Strongrate’s catalog tables describe static loading at ambient temperature. A chemical rating does not extend those structural conditions to hot service, sustained loading or dynamic loads. Have the project engineer review the combined environment and loading before approving the span.

Include clips, supports, fasteners and field fabrication in the review. Industry guide specifications call for compatible resin sealing of cut edges. Specify the sealing procedure in the installation scope, along with inspection of fabricated openings. Record the material specified for clips and supports alongside the panel resin so the assembly review covers each exposed component.

• Send the exposure schedule, safety data sheets, required resin and any written material specification.
• Attach the panel layout, support details, design loads, cutouts, surface requirement and intended cleaning procedure.
• Request identification of the proposed resin system, applicable chemical-chart conditions and any project-specific test or review needed.
• Use the fiberglass grating specification guide to organize submittals and the grating technical resource library for related checks.