Chemical Resistant Fibreglass Cable Tray 150mm-800mm Width Vinyl Ester Resin Build

Chemical Resistant GRP Cable Tray for Petrochemical Industry

1. The Core Functional Advantages of Chemical Resistant GRP Cable Trays in Petrochemical Plants

The petrochemical industry presents one of the most hostile environments for any cable management system. Continuous exposure to aggressive chemicals, hydrogen sulphide, saline atmospheres, acids, and explosive vapours means that traditional galvanised steel trays can corrode within just a few years, requiring frequent replacement and costly shutdowns. Chemical resistant GRP (Glass Reinforced Plastic) cable trays, also known as FRP (Fiberglass Reinforced Plastic) trays, offer a fundamentally different approach. Manufactured from pultruded glass fibre composites with a thermosetting resin matrix, GRP trays are inherently immune to corrosion from most chemicals, atmospheric exposure, UV radiation, and saline conditions—even hydrogen sulphide and chlorine, which rapidly attack stainless steel alloys. Unlike steel, GRP is non-sparking, a critical safety property in explosive atmospheres where even a minor spark from tool impact or cable friction can ignite accumulated hydrocarbon vapours. The material is also non-conductive with high dielectric strength, eliminating the need for earthing of the tray itself and reducing the risk of short circuits in live maintenance scenarios. Weighing approximately 40% less than steel, GRP trays substantially reduce handling effort, structural loading on pipe racks, and installation time—especially beneficial in congested process areas where crane access is limited. With a service life exceeding 30 years and minimal maintenance requirements, GRP cable trays deliver a significantly lower total cost of ownership compared to metallic alternatives, even accounting for their higher initial unit cost.

2. Application Scenarios and Their Corresponding Certification Requirements

Different zones within a petrochemical facility impose distinct regulatory and certification demands on chemical resistant GRP cable trays, and specifying the correct product for each zone is essential for both safety compliance and operational reliability. In classified hazardous areas—Zone 1 and Zone 2, as defined by IEC 60079—GRP trays must be manufactured with anti-static resin to prevent electrostatic charge accumulation that could trigger an explosion; these trays contain carbon additives to provide controlled conductivity and must comply with ATEX and IECEx requirements for equipment used in explosive atmospheres. Although cable trays themselves are not typically “certified equipment” under ATEX, their material selection and bonding arrangements directly influence installation compliance. In process areas handling concentrated acids and alkalis—such as sulphuric acid plants or effluent treatment units—the tray must demonstrate resistance to specific chemical agents, and vinyl ester resin is the standard specification for these applications due to its superior chemical resistance against fuels, vapours, and aggressive chemicals. For onshore and offshore installations in the Middle East, where ambient temperatures regularly exceed 50 °C and salt spray is pervasive, trays must comply with IEC 61537 and carry SASO/SABER conformity for Saudi projects or ADNOC and Aramco specifications for UAE facilities, alongside additional requirements for PVC insulation components rated at 90 °C or higher. Fire performance certification is equally critical: GRP trays must achieve ASTM E84 Class 1 flame spread rating, UL 94 V-0 self-extinguishing classification, and halogen-free low-smoke emission to ensure that a fire event does not produce toxic fumes that could incapacitate personnel in enclosed process buildings. In addition, the UK and European markets require compliance with BS 476 Part 6 and Part 7, while marine and offshore projects often reference NF F 16-101 fire behaviour standards for rolling stock applications.

3. Specification Types and Their Suitability for Petrochemical Applications

BENDIN Chemical resistant GRP cable trays are available in three principal structural configurations, each with distinct performance characteristics suited to different petrochemical applications. Ladder-type trays consist of two pultruded side rails connected by rungs, typically spaced at 6, 9, or 12 inches on centre. This open design provides excellent ventilation and heat dissipation—essential in petrochemical plants where dense cable bundles carrying high-current power cables can otherwise trap heat and accelerate insulation degradation—and allows easy cable inspection and re-routing during turnaround maintenance. Perforated pressed trays feature a moulded base with perforations that allow airflow while providing a degree of shielding from falling debris and chemical drips. Solid trough-type trays offer a fully enclosed base that maximises protection against chemical ingress, making them suitable for areas with concentrated chemical spill risk, such as acid loading terminals and pump areas. Channel-type trays provide a semi-open compromise between the two extremes. In terms of resin systems, the choice is application-driven. Standard polyester resin (PC1) provides good all-round chemical resistance, mechanical strength, and fire behaviour at the most economical cost. Vinyl ester resin is specified for highly corrosive service, including concentrated sulphuric acid, hydrochloric acid, and hydrocarbon vapours, offering significantly enhanced chemical resistance against most fuels, vapours, and aggressive chemical agents. For explosive atmospheres, carbon-loaded anti-static resin provides controlled conductivity to prevent static charge accumulation, satisfying the requirements for use in Zone 1 and Zone 2 hazardous areas. Load classification follows NEMA FG 1, which designates three working load classes: Class A at 50 lbs per linear foot, Class B at 75 lbs per linear foot, and Class C at 100 lbs per linear foot. Standard usable inside widths range from 150 mm to 900 mm, with side rail heights from 60 mm to 110 mm to accommodate varying cable volumes and weights.

4. Installation Considerations: Support Spacing, Thermal Expansion, Bonding, and Cutting

Installing chemical resistant GRP cable trays in petrochemical facilities requires attention to several factors that differ significantly from steel tray practice, and failure to account for them can lead to structural failure, electrical hazards, and unplanned shutdowns. The most critical consideration is support spacing. GRP has a modulus of elasticity approximately one-tenth that of steel, meaning that an identically sized tray will deflect considerably more under the same load. For fibreglass (FRP) trays in chemical plant environments, support spacing should generally be limited to 2 to 3 metres, compared with 3 to 6 metres for stainless steel trays. Junction fittings should be supported within 200 mm, and every cable entry point on a fitting must have an accompanying support. Thermal expansion is another critical consideration that must be addressed during design. GRP expands approximately 1.5 to 2 times more than steel over equivalent temperature variations. Expansion plates should be installed at intervals of 30 to 50 metres to allow the tray to move safely with temperature changes. Built-in self-adjusting interlocking couplers can automatically provide expansion joints for thermal movement, and when expansion splice plates are used, the support nearest the midpoint between two expansion joints should be anchored to allow longitudinal movement in both directions. Regarding bonding and grounding in hazardous zones, while GRP trays themselves are non-conductive and do not require earthing, electrostatic discharge in explosive atmospheres remains a serious concern. In Zone 1 and Zone 2 areas, an independent earthing conductor must be routed alongside the tray and bonded to the facility's grounding network, and anti-static resin trays should be specified to ensure conductivity across the tray surface. Finally, cutting and drilling GRP trays can be performed on-site with standard power tools, but a tungsten carbide-tipped cross-cut saw is recommended for clean cuts, and all cut edges should be sealed with resin to prevent moisture ingress that can cause delamination in humid or chemical environments.

Certification Requirements for Chemical Resistant GRP Cable Trays

Common Specifications of Chemical Resistant GRP Cable Trays