FRP Grating Case Study | Chemical Plant Acid Area Walkway — ZeAllgrate
Chemical Processing — Project Background
A large chemical processing plant in Southeast Asia operated a steel walkway deck throughout its hydrochloric acid (HCl) and sulfuric acid (H₂SO₄) handling area. After 6 years in service, the steel floor plates had corroded through in several bays, required annual weld repairs and patch plates, and produced recurring safety complaints from operators working in a wet, fume-rich environment. Plant engineering estimated that another two coating cycles would not stop structural loss, and requested a corrosion-proof replacement with minimal maintenance.
The replacement had to match the existing support steel spacing, install with the plant's available shutdown window, hold the OSHA 3.5 kN/m² pedestrian live load, and withstand intermittent acid splashes and ambient acid fumes. No client name is published by agreement; the project is described here as Confidential Client, a large chemical manufacturer in Southeast Asia.
Engineering Specification
Working values agreed with the client's engineering team during design review.
| Parameter | Selected Value | Standard / Reference |
|---|---|---|
| Pedestrian live load | 3.5 kN/m² (≈ 72 lb/ft²) | OSHA 29 CFR 1910 / EN 13374 |
| Clear span | 0.9 m between support steel | ZeAllgrate molded grating design guide |
| Deflection limit | L/150 at design load | ZeAllgrate / ISO 14125 Class II |
| Resin system | ZeAll VE (iso-phthalic based vinyl ester) | Resistance to HCl 30%, H₂SO₄ 50% at ambient |
| Reinforcement | E-glass woven roving + chopped mat, molded | ZeAllgrate MR series equivalent |
| Panel thickness | 38 mm, standard mesh 38×38 mm | ZeAllgrate standard molded grating |
| Surface | Grit-top (quartz aggregate bonded with resin) | Wet / acid-spill anti-slip |
| Fixings | SS316 G-clips, 4 clips per panel corner | ASTM A276 / A479 316 |
| Support steel | Existing, abrasive-blasted and epoxy-painted | SSPC-SP10 surface prep |
What Was Supplied and How It Went In
ZeAllgrate engineered and supplied 240 m² of 38 mm ZeAll VE molded grating with bonded grit-top surface. Panels were factory-cut to the plant's walkway layout, with custom notches around pipe stands and valve stations. All panels were delivered with mill-batch resin certificates and acid-immersion test reports against the client's chemical list.
Installation was completed over 3 planned shutdown days. The existing support steel was abrasive-blasted to SSPC-SP10 and coated with a high-build epoxy, then the FRP panels were clip-mounted with SS316 G-clips — no hot work, no welding, and no damage to adjacent lines. Workers reported immediate improvement underfoot because the grit-top surface stayed dry-looking even after acid washdown.
FRP grating walkway in chemical plant acid area
38 mm vinyl ester molded grating panel ready for installation
Corrosion-resistant walkway in acid process area
Outcomes and Inspection Findings
A 2-year follow-up inspection showed zero corrosion on the FRP panels, zero coating breakdown on the clip hardware, and no patching or touch-up work of any kind. Plant safety records show no walkway-related slip or trip incidents during the period.
- Service life estimate: ~25 years for the ZeAll VE system vs. 6 years for the previous steel walkway (coated and patched).
- Maintenance: zero recurring painting or welding — estimated ~40% lifecycle cost saving over 15 years vs. steel replacement.
- Safety: grit-top surface retained wet coefficient of friction > 0.7 at inspection, measured per ASTM F1679.
- Schedule: installation completed within the 3-day shutdown window with no overrun.
Engineering Notes
Acid-area walkways live over the chemical list, so the resin decision is the specification: isophthalic covers dilute ambient service, vinyl ester is the default for strong acids and oxidizers, and novolac extends into hot strong-acid zones. Every chemical is verified at its concentration and temperature against the compatibility chart, and the deck is specified to the worst exposure on each zone rather than the plant average. Grit-top handles the wet corrosive walkway surface; SS316 hardware avoids the galvanic failure that mixed alloys would invite in the same atmosphere.
What to Specify
- Resin per the chemical list (vinyl ester for strong acids; novolac for hot service).
- Grit-top surface for wet walkways; molded or pultruded per span.
- SS316 clips and fasteners throughout.
- E84 fire class confirmed for rated areas.
- Resin per the chemical list (vinyl ester for strong acids; novolac for hot service).
- Grit-top surface for wet walkways; molded or pultruded per span.
- SS316 clips and fasteners throughout.
- E84 fire class confirmed for rated areas.
Planning a Similar FRP Grating Project?
Send us your layout drawings, service chemicals and span requirements — ZeAllgrate will return a design proposal, load calculation and reference pricing within 48 hours.
- ZeAllgrate molded grating design guide, load and deflection tables.
- ASTM F1679 — Standard Test Method for Measuring the Dynamic Coefficient of Friction on Walking Surfaces.
- OSHA 29 CFR 1910 — Walking-Working Surfaces and personal protection standards.
- Project inspection records supplied by Confidential Client; values quoted as-reported.