Stålrör och rördelar för land- och vattenbelagda rörledningar - Utvändig beläggning av polyuretan- och polyuretanmodifierade material
This European Standard specifies the requirements of liquid applied external coating, polyurethane (PUR) and polyurethane-modified (PUR-MOD), for the corrosion protection of tubes and pipeline fittings. The coating in this standard can be applied to longitudinally or spirally welded and to seamless steel tubes and fittings used for the construction of pipelines for conveying liquids or gases. In accordance with the elongation properties, if the component has to be cold bent the coating shall be applied after bending unless otherwise approved by the purchaser. The coating shall consist normally of one layer of liquid product, applied by brush or by an airless spray technique. Other application methods can be recommended by the product manufacturer, in accordance with the kind of product (spatula, injection, spreading, etc.). This coating can be used for the protection of buried or submerged steel tubes for service at the following temperatures and with two thickness classes A (1 000 um) and B (1 500 um) based on the following combination. Lower thickness can be agreed between the coating manufacturer and the purchaser. - type 1 : - 20 oC to 40 oC, thickness class A or B - type 2 : - 20 oC to 60 oC, thickness class B - type 3 : - 20 oC to 80 oC, thickness class B Other temperatures can be agreed; in this case, tests shall be carried out at the required temperature. In this standard the word components is used for tubes and fittings. Frequencies of tests on fittings shall be agreed by the parties at the ordering stage. Components coated with these types of coatings may be further protected by means of cathodic protection.