AWWA C225:2003 pdf download.Fused Polyolefin Coating Systems for the Exterior of Steel Water Pipelines
AWWA C225 describes the materals and application of fused polyolefin coating systems for buried service. This system is applied in pipe coating plants, both portable and fixed, using coating techniques and equipment as recommended by the manufacturer. Normally, these prefabricated, polyolefin coatings are applied as a three-layer system consisting of (1) a liquid adhesive, (2) a corrosion- protection inner layer, and (3) a mechanical-protection outer layer. This standard establishes the minimum requirements for fused polyolefin coating systems.
1.1.1 Maximum temperatures. This standard is intended for pipe in potable- water service. Therefore, the maximum service temperature of this coating is based on the maximum service temperature of potable water. These coating systems will perform at higher temperatures. Consult the coating manufacturer for conditions and limitations.
4.3.1 System components The prefabricated polyolefin fused coating system shall be at least three layers consisting of the following: 1. A liquid adhesive layer. 2. An inner layer for corrosion protection. . 3. An outer layer for mechanical protection. The inner -layer corrosion protection and outer-layer mechanical protection shall be in the form of prefabricated material in rolls. The properties of the entire system shall conform to the appropriate values listed in Tables 1, 2, 3, and 4.3.1.1 Liquid adhesive. The liquid adhesive shall consist of a mixture of suitable rubber and heat or thermal activated polymeric resins and a solvent.' The liquid adhesive shall be applied to the properly prepared pipe surface before application of the inner-layer corrosion protection. The function of the liquid adhesive is to provide a bonding medium between the pipe surface and the inner- layer corrosion protection. Future air emission regulations may estrict the use of liquid adhesives described in this standard. If this occurs, consult the manufacturer for equivalent alternatives.
4.3.1.2 Inner-layer corrosion protection. The inner layer shall be a two-layer pre-formed flm, consisting of a synthetic cross-linked (butyl-based) elastomer adhesive laminated to a polyolefin-based polymeric alloyed backing. The manufac- turer shall certify that the backing material shall be polyolefin only, containing not less than 1.0 percent nor more than 3.5 percent, by weight, of nonpolyolefinic material consisting of carbon black and antioxidants. The inner layer shall be applied after the liquid adhesive and before the outer layer. The primary purpose of the inner layer is to provide corrosion protection.AWWA C225 pdf download.