B1 & E-39

In the European standard EN 10240 (which covers internal and external protective coatings for steel tubes), B.1 is a specific coating grade.

• Definition: It refers to a hot-dip galvanized coating intended for tubes used in applications other than potable (drinking) water.

• Characteristics: While Grade A.1 is strictly for drinking water and requires a smooth, high-purity internal surface, Grade B.1 is used for general-purpose fluid conveyance like cooling water, fire protection, and gas.

• Requirements: It ensures a consistent zinc layer that provides excellent atmospheric corrosion resistance but has slightly different chemical and surface requirements compared to the "food-grade" A.1 standard.