AWWA C224:2002 pdf download.TWO-LAYER NYLON-11-BASED POLYAMIDE COATINGSYSTEM FOR THE INTERIOR AND EXTERIOR OF STEEL WATER PIPE, CONNECTIONS, FITTINGS, AND SPECIAL SECTIONS
4.5.1 General. Polyamide coatings shall be applied by a method specifed by the manufacturer. When the same coating is to be applied to both the internal surface and external surface of the steel article, it is usually preferable to employ the method of immersion in a fluidized bed. When the coating is to be applied to either the internal surface or the external surface of a steel article, but not both, it is usually preferable to employ either the method of electrostatic spray or the method of spray onto a preheated article. When different coatings are used for internal surface and external surface, it may be preferable to employ the method of rotocoating (a method whereby the coating is applied to the interior surface of a pipe by rotating the pipe [heated} with polyamide powder inside). Note, however, that because elevated temperatures are required to perform rotocoating, coatings that have been applied prior to rotocoating may be damaged.
4.5.2.1 Weld reinforcements. Weld reinforcements (ie, the raised compo- nents of weld seams) in a steel article shall be deburred or may be removed when required by the purchaser, such that the area formerly under the weld reinforcement is flush to all adjacent surfaces. When performed, removal of weld reinforcements shall be performed prior to hydrostatic testing, surface cleaning, or abrasive blast cleaning.
4.5.2.2 Surface cleaning. Prior to the performance of abrasive blast cleaning, steel surfaces shall be inspected and, if required, cleaned according to SSPC SP-1 to . remove oil, grease, or other adhering deposits. Care shall be taken to ensure that use of solvents complies with applicable local regulations. Heating to remove water and ice may be performed, provided that steel surfaces are heated in a manner that prevents distortion and other damage. If any contaminant remains after cleaning, more vigorous cleaning steps (e.g, chemical treatment) may be needed.
4.5.2.3 Abrasive blast cleaning. Abrasive blast cleaning shall be performed. It shall be performed in accordance with the specifications of SSPC SP-10NACE No.2 in order to achieve a near-white surface.AWWA C224 pdf download.