Overview
EN ISO 11177:2019 (CEN endorsement of ISO 11177:2019) sets product quality requirements and testing procedures for vitreous and porcelain enamels applied to the inside and outside of valves and pressure pipe fittings used in untreated and potable water supply. It defines the acceptable enamel surface quality, coating thickness, mechanical and chemical resistance tests, and reporting expectations. The standard does not apply to chemical-service glass-enamels or apparatus enamel.
Key topics and technical requirements
- Scope & applicability
- Covers enamelled valves and pressure pipe fittings for potable and untreated water systems.
- Sampling to be agreed contractually between buyer and supplier.
- Surface quality
- Enamelling must be uniform and smooth; sealing surfaces must preserve seal performance.
- Isolated pores acceptable if ≤ 1 mm and no more than seven pores on a ~35 mm diameter surface segment.
- Coat thickness
- Measured per ISO 2178 (magnetic method).
- Flat surfaces: 200–600 µm; edges, undercuts and ridges: minimum 150 µm.
- Hardness
- Surface scratch hardness per EN 15771 (Mohs scale): ≥ 4.
- Thermal shock
- Tested per ISO 13807 with a temperature difference of 200 K and water cooling; no visible defects allowed after test.
- Corrosion & chemical resistance
- Water/steam resistance per ISO 28706-2; no blistering, partial delamination or pitting permitted.
- Includes tests for resistance to citric acid, acid soil, sub-surface migration after impact, scratch and abrasion damage, and resistance to climatic exposure/UV.
- Other
- Physiological harmlessness assessment and a formal test report detailing methods and results are required.
Practical applications and users
EN ISO 11177:2019 is essential for:
- Manufacturers of enamelled valves and pressure pipe fittings ensuring compliance with quality and durability requirements.
- Testing laboratories performing accredited enamel tests (abrasion, scratch, corrosion, thermal shock, UV).
- Water utilities and municipalities specifying fittings for potable water networks.
- Procurement and quality assurance teams writing technical specifications and acceptance criteria.
- Engineers and consultants advising on material selection for long-term corrosion resistance in water systems.
Related standards
Normative references and related test methods commonly used alongside EN ISO 11177:2019:
Using EN ISO 11177:2019 helps ensure enamelled pipeline components meet recognized quality, durability, and health-safety expectations for potable water infrastructure.