AWWA C214:2000 pdf download.TAPE COATING SYSTEMS FOR THE EXTERIOR OF STEEL WATER PIPELINES
This standard describes the materials and application of tape coating systems in coating plants at fixed sites using coating techniques and equipment as recom- mended by the tape coating manufacturer. For normal construction considerations, prefabricated polyolefin tapes are applied as a three-layer system consisting of (1) liquid adhesive, (2) corrosion-preventive tape (inner layer), and (3) mechanical- protective tape (outer layer). This standard establishes the minimum requirements for tape coating systems used on the exterior of steel water pipelines in the potable-water supply industry. Continuous monitoring of all application procedures for the tape coating systems shall be done by the constructor.
1.1.1 Maximum temperatures. All AWWA pipe coating standards are intended for 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 manufac- turer for conditions and limitations.
4.3.1.1 Liquid adhesive. The liquid adhesive shall consist of a mixture of suitable rubber and synthetic compounds and a solvent. The liquid adhesive shall be applied to the properly prepared pipe surface before application of the inner-layer tape. The function of the liquid adhesive is to provide a bonding medium between the pipe surface and the inner-layer tape. Future air emission rules may regulate the use of liquid adhesives described in this standard. If this occurs, consult the manufac- turer for equivalent alternatives.
4.3.1.2 Inner-layer tape. The inner-layer tape shall be a two-layer tape consisting of a polyolefin (only) backing layer with a laminated butyl-based adhesive layer. The inner tape shall be compatible with the liquid adhesive. The manufacturer 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 tape shall be applied after the liquid adhesive and before the outer-layer tape. The primary purpose of the inner-layer tape is to provide corrosion protection.AWWA C214 pdf download.