ISO 24817 Petroleum, Petrochemical and Natural Gas Industries - Composite Repairs for Piping - Qualification and Design, Installation, Testing and Inspection

The ISO 24817 “Oil, petrochemical and natural gas industries – Composite repairs for piping – Qualification and design, installation, testing and inspection” standard, developed by the International Organization for Standardization (ISO), describes and offers recommendations for the qualification, design, installation, testing and inspection of composite repair systems for external application to worn or damaged pipelines, tanks and vessels used in the oil, petrochemical and natural gas industries.

For the purposes of this standard, the following terms and definitions apply:

• Anisotropic is one that exhibits different physical properties in different directions.
• Barcol hardness is the measurement of surface hardness using a surface depressor.
• A bubble is an air gap between layers within a laminate, appearing as a raised area on the surface.
• Composite is a thermoset resin system reinforced with fibers.
• A crack is a split in the laminate that extends from the wall (perpendicular to the surface) and is a true separation where the opposing surfaces are visible.
• Curing is the setting of a thermoset resin system, such as polyester or epoxy, by an irreversible chemical reaction.
• The cure schedule is the time-temperature profile appropriate to produce a specified Tg or heat distortion temperature.
• Defect type A is a defect within the substrate, which does not penetrate the wall, and is not expected to penetrate the wall within the repair design life of the repair system.
• Defect type B is the defect passing through the wall or the substrate where the remaining wall thickness at the end of service life is less than 1 mm.
• The defined life is the actual application or service life of the repair.
• Delamination is the area between the repair laminate and the substrate where there should be bonding but no bond exists, or the area of ​​separation between layers in the repair laminate.
• Design life is the maximum operational life of the repair.
• Differential scanning calorimetry (DSC) is a method of determining the glass transition temperature of thermosetting resin.
• A dry spot or uncured/dry fiber is the area of ​​the fiber where bare, exposed fibers are visible and not impregnated with resin.

The qualification and design, installation, testing and inspection procedures for composite repair systems in this international standard cover situations involving the repair of damage commonly encountered in oil, gas and utility piping systems and vessels. The procedures are also applicable to the repair of pipelines, caissons and storage tanks with appropriate assessment.

These procedures cover the repair of metallic and GRP pipelines, pipeline components, originally designed pipelines in accordance with various standards including ISO and ASME.

This standard is not a defect evaluation standard. There is no statement in this standard regarding whether a particular defect is acceptable or unacceptable for repair. The standard assumes that a defect evaluation has already been performed, for example, according to an ASME standard. The starting point for this standard is that a decision has been made to repair a particular defect with a composite repair system and that the output from the defect evaluation is used as input for the repair design. This standard deals with the subsequent activities of repair qualification, design, installation and inspection.

Repair systems are applied to restore structural integrity. For example, addressing whether an external corrosion defect has penetrated through a wall. In this case, applying a repair system will usually stop further deterioration.

In short, corrosion in metallic industrial equipment, pipelines and vessels can lead to complete wall failure if left unchecked. The presence of through-wall defects can lead to environmental and safety hazards, as well as lost production and costly downtime. One solution to this problem is to install a repair system using composite materials, which are durable for decades, easy to install and a cost-effective option to deploy to restore industrial equipment to working order even after a leak is detected. International organizations such as ASME and ISO specify design methodologies and material testing for such repair methods.

Part of the testing program that composite repair systems must undergo for qualification is installation in pipes of various bore sizes followed by pressure testing. The purpose of these tests is to determine the lower confidence level of the energy release rate of the repair system. One requirement set by the standards to calculate this is that failure must occur at the edges of the repair rather than through its thickness. However, in order to have a consistent edge failure mode, the number of layers of the composite repair may be thicker than mathematically predicted. This standard provides a procedure for evaluating the leak-sealing capabilities of composite repairs of various thicknesses.

Among the numerous testing, measurement, analysis and evaluation studies that our organization has provided for businesses in various sectors, with its trained and expert staff and advanced technological equipment, it also provides testing services defined in the “ISO 24817 Petroleum, petrochemical and natural gas industries - Composite repairs for piping - Qualification and design, installation, testing and inspection” standard.