Coatings generally refer to the protective barrier applied to the exterior surfaces of any structure. Coatings may be exposed to the atmosphere, buried conditions, immersed conditions or specific corrosive environments (such as in a chemical plant scenario)
Linings generally refer to the protective barrier applied to the internal surfaces of pipelines and tanks. Linings are almost always subjected to immersion conditions, which may also be chemically aggressive.
The variety and efficacy of coatings is a vast and specialised field. Careful selection of appropriate coatings and linings is critical to ensure a fit-for-purpose asset. Isinyithi can assist clients in this process.
The key factors which should be considered in any coating or lining include:
- Appropriate coating / lining selection to ensure that the products selected are fit-for-purpose. This will include considering the anticipated service, environmental and thermal conditions, start-up and operating conditions and parameters, life expectancy, substrate material, compatibility with cathodic protection (if applicable), and in the case of pipelines, the pipe diameter and the material being transported
- Coating/lining selection should also take the total life cycle costing and service maintenance intervals into consideration
- In the case of pipelines, careful consideration of field joint coating repair, both internally and externally must be taken into account.
- Development of a practical yet detailed and thorough coating specification
- Quality Control/Assurance during coating/lining manufacture, application and installation
- Surface preparation prior to application of the coating/lining
- Careful selection of the method of coating application is critical
- Examples of coating and lining materials include: epoxy, polyurethane, polyethylene, bitumen and cement/concrete