High quality painting of piping and equipments as well as structures, is essential to avoid corrosion. It helps ensure long life of a constructed plant and low maintenance costs. Painting involves not only total surface cover but also markings of various types such as line numbers, fluid codes, flow arrows, equipment numbers etc.
Painting specification for the project is given by PMC or Client in FEED or BEP. It is updated by material engineer on the project. Engineering firm can use its own standard painting specification if allowed by client.
Preparation of painting specification involves understanding environmental factors, location of piping (indoor or outdoor), insulation requirements, operating and design temperatures. It may also involve local rules and regulations as well as availability of materials.
Applicability of Standards
Painting Specification is prepared by Material Engineer to assure high quality painting work on the project as per international standards. Various international codes and standards should be followed for painting.
Painting includes surface preparation, selection of paints, application of paints on external surface of piping and equipments. Final painting shouldbe done only after all tests are performed on the piping system. Surface preparation is critical to ensure clean surface so that paint film adheres securely to the surface. Various methods of surface preparation are used like Hand Tool Cleaning, Power tool, Blast Cleaning etc. Environmental factors such as Rain, Wind, Temperature, Humidity must be considered while painting. Normally primare should be applied within 4 hours of surface preparation. Paint is applied using brush, air spray equipment etc. as per relevent standards.
Components Requiring Painting
- Un-insulated carbon steel pipes, fittings, valves, special items etc. require painting.
- Carbon steel ducts, furnaces and stacks require painting.
- All un-insulated equipments like columns, vessels, drums, heat exchangers, pumps, compressors, electrical panels, motors etc. require painting.
- All structural componets like steel members, platforms, ladders,handrails etc. required painting.
Insulated Lines and Equipments
Painting of markings over insulation cladding is required on all piping for identification of lines. In some cases, painting under insulation also required for carbon steel piping.
Plastic or plastic coated components do not required to be painted. Various markings may be done on plastic piping for identification purpose.
Stainless Steel Piping
Stainless steel piping is not painted. Identification marking may be done on this piping.
Non-ferrous materials like Aluminium are not required to be painted.
Proper documentation regarding painting process must be maintained by the contractor and submitted to the client.
Field safety and hygiene must be maintained at all times during painting work.