Most of our products are as standard with internal and external epoxy coating (according to DIN30677-2 & GSK guidelines). The coating layer is either applied manually or by using a fluidised bed epoxy coating system. Prior to applying the epoxy, all cast parts are blast cleaned to eliminate any unevenness and to provide the perfect adhesion of the coating. The process involves powder applied to a preheated component causing the powder to melt. The component then enters a cooling tunnel and the melted powder cures.
The AVK Group also offers products with external PUR coating. PUR is developed for use in steel gas pipes with cathode protection, but is also a good choice for installation in aggressive soils. Additionally, we offer products with a wear-resistant internal enamel lining. This offers great protection against creeping corrosion due to chemical fusion of the lining and the ductile iron.
To assure high quality and consistency, our products are carefully tested in the following areas;
Layer thickness check; the epoxy coating layer thickness in minimum 250 μm according to DIN 30677-2 and GSK requirements.
Cross linkage test; to detect possible imperfections in the epoxy coating, methyl isobutyl ketone is applied and wiped away with a cloth after 30 seconds. In order to pass the test, the cloth must not show any signs of coating.
Impact resistance test; a stainless steel cylinder is dropped on the epoxy coating surface with an impact energy of 5 Nm. After impact, the component is electrically tested and no breakthrough shall occur.
Holiday detection; a detector with a brush electrode is used to reveal and locate any pores in the coating.
In addition, the independent GSK authorities monitor and approve our coating process several times a year through adhesion and cathode disbonding tests. The GSK Quality Assurance Association for Heavy-Duty Corrosion Protection of Valves and Fittings with Powder Coating (GSK e.V.) is the international industry network for businesses that coat valves and fittings with epoxy powder. GSK awards the RAL-GZ 662 Quality Mark (Gütezeichen) to companies who fulfil the strenuous quality-assurance requirements in accordance with the current Quality and Inspection Regulations. Learn more on their website here.
Watch the videos below and learn more about our cleaning and coating processes.