Design and maintenance of fibreglass reinforce plastics (FRP) and dual laminate (FRP + thermoplastics) equipment for hydrochloric acid service

摘要

Hydrochloric acid is a commonly used substance in the chemical industry. Being so aggressive, it is required to be cautious when choosing the grade of the materials used for manufacturing non metallic components. The substances diluted on the hydrochloric acid must also be considered, since they could increase the chemical attack even at very low amounts. Vessels and pipelines for hydrochloric acid are needed today at very demanding conditions (pressure and temperature), so it is very important to apply thoroughly a good design code, being EN 13121 [1] and ASME RTP-1 [2] the most advisable for those materials. It is also highly recommended to apply the construction details for secondary bonding shown in document DT-15 Rev. 1 from UIC [3], and the use of other procedures that could increase the structural homogeneity of the material. But not only the design and fabrication procedures are important for these vessels and piping, a well performed quality control is required along the whole fabrication process, in order to obtain a satisfactory and reliable product at the end. Finally, hydrochloric acid attack will progress very easily through any defect on the corrosion resistant barrier or liner. As a result, performing a good preventive inspection plan (visual inspections, microscope examination of samples, and hydrostatic tests controlled through acoustic emission) in order to diagnose any defect that could appear on the laminate should be compulsory.