Overview
EN ISO 15741:2021 (ISO 15741:2016 adopted by CEN) specifies requirements and test methods for friction‑reduction coatings - principally liquid epoxy paints - applied to the interior of on‑ and offshore steel pipelines used to transport non‑corrosive gases. The standard covers material qualification, application (normally shop‑applied), production control, testing of cured films and operational handling, including packaging, storage and repairs. The coating is typically a single, smooth, spray‑applied layer (airless spray or equivalent); brush application is restricted to small repairs.
Key topics and requirements
- Coating material specification
- Qualification parameters: non‑volatile matter (mass/volume), viscosity, density, pot life, ash (residue on ignition), infrared spectrograms, appearance.
- Cured film properties and tests
- Dry film thickness measurement, adhesion, Buchholz hardness, bend (conical mandrel) test, resistance to neutral salt spray, artificial ageing, water immersion, chemical resistance, resistance to gas pressure variations, hydraulic blistering.
- Normative test methods and annexes: ash determination, porosity, curing test, wet‑sponge test, pressure and blistering procedures.
- Application and surface preparation
- Surface preparation of blast‑cleaned steel, paint preparation, recommended application techniques (shop spray), and requirements to achieve a smooth cured film for friction reduction.
- Production control and quality assurance
- On‑pipe and panel assessment (appearance, thickness, adhesion), batch test certificates, product data sheets, qualification and quality records.
- Handling and logistics
- Storage, transportation, handling of coated pipes and guidance for loading and repair procedures.
Applications and users
- Practical uses:
- Internal friction‑reduction coatings in transmission pipelines (onshore and offshore) conveying non‑corrosive gases where reduced hydraulic/friction losses are required.
- Shop application during pipe fabrication to improve flow efficiency and protect against minor handling damage.
- Primary users:
- Pipeline owners and operators, epoxy coating manufacturers, pipe fabricators, coatings applicators, QA/QC engineers, inspection bodies and procurement/specification writers involved in gas pipeline projects.
Related standards and committees
- Developed by ISO/TC 35 “Paints and varnishes” and adopted by CEN/TC 139 “Paints and varnishes”.
- EN ISO 15741:2021 aligns with ISO 15741:2016; users should coordinate with other industry standards for pipeline engineering, corrosion protection and project specifications.
Keywords: EN ISO 15741:2021, friction‑reduction coatings, epoxy paints, internal pipeline coatings, onshore offshore steel pipelines, non‑corrosive gases, dry film thickness, adhesion, surface preparation, production control.