Paints and varnishes - Friction-reduction coatings for the interior of on- and offshore steel pipelines for non-corrosive gases
1Key Takeaways
This document specifies reduirements and methods oftestfor liquid epoxypaints and internal coatings of such paints in steel pipes and fittings for the conveyance of non-corrosive gas. It also deals with the application ofthe paint. Other paints or paint Systems are not excluded provided they comply with the redquiremen…
2Expert Interpretation
An in-depth analysis of ISO 15741:2016, the international standard for anti-friction coatings on the inner walls of steel pipelines for non-corrosive gas transportation, covering the technical specifications, performance test methods, and construction quality control points of epoxy coatings. It is applicable to both onshore and offshore pipeline projects.
Core requirements of the standard
| Technical indicators | Test method | Qualification standard |
|---|---|---|
| Dry film thickness | ISO 19840 | 60-100μm |
| Adhesion | ISO 2409 | ≤Grade 1 |
| Salt spray corrosion resistance | ISO 9227 | No deterioration after 480h |
| Chemical resistance | ISO 2812-1 | 6 liquids 168h test |
Technical requirements for coating materials
The standard stipulates that two-component epoxy coating should be used. The key performance indicators include:
- Non-volatile matter content (mass/volume) meets the manufacturer's declared value
- Viscosity range meets construction requirements
- Density error ≤±5%
- Ash residue ≤ specified limit
Construction quality control
Surface preparation requirements
Must meet the Sa2.5 level specified in ISO 8501-1, with a surface profile of 25-60μm (ISO 8503-2). During application, the substrate temperature must be 3°C higher than the dew point and not lower than the minimum curing temperature required by the coating.
Production Inspection Frequency
| Inspection Items | Frequency |
|---|---|
| Dry Film Thickness | Twice per shift |
| Porosity Test | Inspection of each batch of glass plates |
| Bending Test | Twice per shift |
Technical Evolution Analysis
Compared with the 2001 version, the 2016 version has the following major updates:
- Added new requirements for Hydraulic Blistering Test (Appendix D)
- Refined the gas pressure cycle test parameters (Appendix C)
- Updated the list of chemical resistance test liquids
- Strengthen quality document system requirements
Implementation suggestions
Phase procurement: Require suppliers to provide complete qualification certificates (4.7) and batch inspection reports (4.8)
Phase construction: Establish a temperature-humidity-dew point monitoring system and record environmental parameters every 2 hours
Phase acceptance: Use a wet sponge detector (Appendix G) to conduct a special porosity inspection