Japan-based Toray Industries has secured type approval from the American Bureau of Shipping (ABS) for the vacuum-assisted resin transfer molding (VaRTM) process for in-situ ship repairs, developed jointly with MODEC.

The technique entails applying carbon fiber reinforced plastic (CFRP) to corroded areas with reduced thicknesses of floating production, storage and offloading (FPSO) and floating storage and offloading (FSO) systems.

ABS is one of the world’s leading classification societies, accounting for around half of FPSO and FSO certifications. This approval enables these certified vessels to employ the proprietary VaRTM process, reducing the time needed for engineering reviews and verifications for ship repairs.

FPSO and FSO maintenance is normally offshore using steel materials. The welding, or hot work, halts oil and gas production.

Toray and MODEC jointly developed the VaRTM repair process in 2020. It entails applying Toray’s TORAYCA carbon fiber woven fabric, which offers excellent strength and elasticity, to the surfaces of existing steel structures. The next step is to cover the fabric with a film, vacuum-seal, and inject epoxy resin that then cures to complete repairs by bonding the CFRP to the steel structures.

In-situ VaRTM process diagram (Credit: Toray Industries)

Another advantage of this in-situ VaRTM process is that it is easier than with regular steel-based techniques to transport materials and equipment to locations and perform repairs faster and with fewer people and time. The procedure does not involve hot work, minimizing impacts on oil and gas production, according to the Japanese company.

Toray said it continue to work on its in-situ VaRTM process for a range of industrial applications while developing repair and reinforcement technologies for FPSOs and FSOs to promptly address market needs.

• MODEC and Toray Develop New FPSO Repair Technique