Q: What is composite material?
A: Composite material is a combination of reinforcing fibres, such as glass fibre, and a polymer matrix. When cured, the composite material can possess a range of properties: glass fibre composite material will have high strength combined with high elasticity, whilst a carbon fibre system can be even stronger with a higher Young's modulus but the greater stiffness imparted may detract from usefulness in some situations.
Q: How does a composite pipe repair work?
A: The first, and most important, part of the application process is surface preparation. The ideal preparation is to SA 2.5 standard, which will achieve optimum adhesion to the substrate. Other levels of surface preparation are achieved by machine or hand abrasion; these may be essential in circumstances where high levels of pipe wall reduction have occurred – it is possible to carry out a repair in such circumstances using IMG Composites products. If the surface of the substrate features a particularly rough profile after surface preparation, then CompoSol® Reinforced Epoxy Paste is applied to provide a smoother surface. Following this, the fabric is impregnated with IMG Composites own CompoSol® polymer matrix and is then applied around the circumference of the pipe. The axial extent and thickness of the repair are determined from the ISO/TS 24817 design standard. After wrapping, the repair is compressed to ensure consolidation and to prevent voids from forming, and is then allowed to cure. A number of in-process inspections are carried out to ensure sufficient adhesion and level of cure have been achieved.
Q: Is it fire rated?
A: IMG Composites epoxy based CompoSol® systems are rated to BS476:Part7, Class 1 for spread of flame resistance, the highest class available, and to BS476:Part6, Class O for Fire Propagation.
Q. Why are composite repairs used so widely on steel?
A: Because they arrest external corrosion by creating a barrier on the steel surface and at the same time provide a designed reinforcement to replace material lost during the previous corrosion process.
Q: Why should I use composites?
A: The IMG Composites range of CompoSol® products do not necessitate the use of heavy plant or equipment that generate sparks and thus they can be applied in a cold work environment.
IMG Composites' materials have a high strength-weight ratio, making the CompoSol® range of products suitable where added weight is undesirable.
Composite material does not corrode, thus it is ideal for structures that are in environments where corrosion is a concern.
The nature of application of IMG Composites' CompoSol® products mean that they are easy to install, and are adaptable to a wide variety of geometries and situations.
IMG Composites' materials have an excellent range of mechanical properties. They are thus able to be used to reinstate the design strength of pressurised pipes and a range of structural members.
IMG Composites is a cost effective solution as CompoSol® products can be applied live and with no loss of production.
Using composite material produces less CO2 than equivalent steel replacement/repair methods.
Q: What is the temperature resistance?
A: This can vary depending on the operating conditions. Generally IMG Composites repairs can be used where the operating temperature is in the range -70oC to 70oC. However, it is possible to modify the temperature cure history so that they can be applicable to structures operating at much higher temperatures.
Q: Are IMG Composites repairs permanent?
A: The international standards use the terms long term and short term repairs. ISO/TS24817 specifies design methods for repairs that will last 2 years, 10 years and 20 years.
Q: How do you prevent corrosion in the steel from propagating?
A: If the corrosion is external, then all rust from the surface is removed during surface preparation. After the defect area has been wrapped, it will no longer suffer from corrosion as it is isolated by the composite barrier.
Q: What if the corrosion is internal?
A: If there is internal corrosion in a pipe, the IMG Composites design will only take into account the pressure retaining capabilities of the composite (i.e. no contribution from the steel). Thus, if the defect area were to become holed through continued corrosion, then the IMG Composites repair is designed to be strong enough to withstand the internal pressure.
Q: What are the limitations of IMG Composites repairs?
A: The IMG Composites CompoSol® products must be applied above 5-10oC in order for them to commence curing. If the temperature during application is too low, then it is possible to use heaters to raise the temperature of the substrate and environment to levels where the repair can cure. Once completely cured, IMG Composites CompoSol® repairs can be exposed to service temperature down to -70oC.
Pressure limitations are not simple to outline as the ability of any material to retain pressure in a pipe is dependent upon both the pressure carried and the diameter of the pipe. IMG Composite repairs have been carried out on lines in excess of 200bar and on pipe diameters as large as 60inches.
Q: What structures can IMG Composites CompoSol® products be applied to?
A: IMG Composites can repair and retrofit all types of pipes, including ferrous/non ferrous metals and plastics. IMG Composites materials are suitable for pipes containing produced water, hydrocarbons, pressurised water, fire water, flammable fluids, gas and other less hazardous fluids.
There are also a number of structural applications that can be repaired or retrofitted by IMG Composites CompoSol® reinforcements due to the flexibility of application and the wet-layup method. Repairs are engineered on a case by case basis and can be used as corrosion protection and structural reinforcement for, but not limited to: pipes and pipelines, tanks and vessels, flat surfaces, beams, columns, and piles. IMG Composites can also repair a wide range of substrates, including metallic-based substrates and concrete.
Q: What happens in fatigue?
A: Propagation of cracks caused by fatigue is mitigated by the nature of IMG Composites material. Crack propagation within the material is prevented due to the boundary between the layers of fibre inside the composite matrix. In addition, the ISO/TS 24817 design standard makes provision for cyclic loading de-rating factors.
Q: What standards/guidelines are used by IMG Composites?
A: IMG Composites CompoSol® products are used in compliance with ISO/TS 24817 design standard for Composite Repairs for Pipework (Qualification, Design and Installation) and ASME PCC2, Articles4.1 and 4.2. These standards were developed in a joint consultation between suppliers and operators. IMG Composites are subjected to regular audit by ACORES (the Association of Composite Repair Suppliers). All services offered use the most up-to-date engineering design methodology.
Q: How much does an IMG Composites CompoSol® repair cost?
A: Each IMG Composites repair is a bespoke design and thus the price will vary from case to case. However it has consistently proved to be a lower cost alternative to other strategies thanks to:
- no down time necessary
- no hot permit to work required
- no loss in production
- relative ease of application.
Q: How long does an IMG Composites CompoSol® repair take?
A: Each IMG Composites repair will vary according to the size and conditions of the structure being repaired. However, application is relatively short compared to other options, in part due to a short lead-in time as no off site fabrication is required. As a guide, a 15m repair of a 24" pipe has been completed within 6 days.
Q: What differentiates IMG Composites CompoSol® from other composite repairs?
A: The advantage of IMG Composites CompoSol® repairs is our expertise. Structural engineering capability enables IMG Composites to design bespoke reinforcement repairs as well as carrying out individual designs for standardised repairs. Chemistry expertise means that CompoSol® resins are uniquely designed, and controlled by IMG Composites, in order to provide the mechanical and other properties necessary for high performance in a range of environments. These properties include high cohesive and adhesive strengths, which results in high performance over a variety of operational envelopes, including substrates that have been prepared to St. 2 (Hand Preparation).
Q: What testing/qualification procedures have IMG Composites material been subjected to?
A: All IMG Composites material is qualified in accordance with ISO/TS 24817 and independently verified. A variety of material testing has also been carried out and IMG Composites continues to do so.
Q: What are the advantages of an IMG Composites CompoSol® repair compared to an equivalent steel repair?
- Corrosion: IMG Composites material does not corrode, giving it a much higher potential lifespan.
- Light-weight: Compared to an equivalent steel repair, an IMG Composites repair is much lighter.
- Cold work: IMG Composites CompoSol® repairs can be applied without a hot permit to work, thus it is applicable to a wider range of environments.
- No Joints/Welds: Joints are not required in an IMG Composites CompoSol® repair whereas the presence of joints (especially welds) in steel repairs is an inherent weakness. This enables a CompoSol® repair to cover much larger areas without weak points.
- Flexibility: IMG Composites are flexible and much more capable of conforming to complex shapes on site without the need for fabrication, thus reducing cost and lead-in times.
- Impact: Under impact loading, an IMG Composites CompoSol® repair is much less susceptible to damage due to the higher elasticity of the composite material. In addition, damaged areas are much more visible in composite than damaged areas in steel.
- Environmental: Manufacturing steel generates 4 tons of CO2 per ton of sheet produced (Transportation R&D Centre, Argonne National Library, Oct 1995). This is compared to 0.75 tons of CO2 per ton of epoxy resin produced.