Overview
EN ISO 28763:2019 - "Vitreous and porcelain enamels - Regenerative, enamelled and packed panels for air‑gas and gas‑gas heat exchangers - Specifications" - defines minimum requirements and functional characteristics for enamel coatings applied to profiled steel panels used in regenerative heat exchangers. It covers enamel application methods (wet dipping, flow‑coating, spraying, electrodeposition, dry‑powder electrostatic spraying), inspection before and after packing in baskets, and notes that stricter limits can be agreed between customer and supplier for very severe service or extended life.
Key Topics and Requirements
- Scope and definitions for air‑gas and gas‑gas heaters (includes service temperatures - hot gases up to 450 °C; normal operation ~320–380 °C).
- Substrate steel requirements: delivery, chemical analysis, hydrogen permeability, fish‑scaling test and pickling speed checks.
- Enamel frit and coating properties: coefficient of thermal expansion, fusion flow, boiling‑water vapour resistance, acid resistance, thermal‑shock resistance and adherence.
- Coating characteristics: adherence, thickness measurement (referenced methods), detection of fundamental and open defects, edge covering of gas‑gas heaters, boiling sulfuric acid resistance and reworkability.
- Packing criteria: packing pressure, visual examination after packing, and post‑packing requirements.
- Testing methods and documentation: normative test methods (e.g., thermal‑shock method in Annex A) and specification of required documentation and inspection certificates.
Practical Applications
- Ensures reliable performance of regenerative heat exchanger panels used in:
- Power plants (air‑gas preheaters)
- Flue‑gas desulfurization and industrial gas‑gas reheaters
- Any process where corrosion resistance, thermal cycling and gas tightness are critical
- Helps manufacturers, enamel suppliers and fabricators to:
- Specify and control enamel production and application processes
- Verify coating adhesion, chemical resistance and thermal‑shock durability
- Ensure panels survive packing and handling without coating failure
Who Uses This Standard
- Heat exchanger manufacturers and fabricators
- Enamel frit producers and coating applicators
- Plant engineers and procurement/specification writers in power, petrochemical and emissions‑control industries
- Quality assurance, inspection and testing laboratories
Related Standards
EN ISO 28763 references and aligns with related test and delivery standards such as:
- ISO 4534 (fusion flow), ISO 2178 (coating thickness), ISO 28706‑2 (chemical corrosion resistance), ISO 28723 (edge covering), and EN 10209 / EN 10204 for steel delivery and inspection documentation.
Using EN ISO 28763:2019 supports consistent specification, testing and acceptance of vitreous and porcelain enamel coatings on regenerative heat‑exchanger panels, improving durability and operational reliability in demanding thermal and corrosive environments.
