1.1This guide will discuss standard practices which have been successfully utilized in the field for over 35 years to provide external corrosion protection of polyethylene encased ductile iron pipe supplemented with cathodic protection (CP). This guide may also be used for ductile iron fittings, valves, and other appurtenances specific to ductile iron pipe systems. Case histories and publications reporting on the use of cathodic protection to supplement polyethylene encasement are included as an Appendix in this guide.
1.2Other external corrosion control methods which have been used for ductile iron pipe include, but are not limited to: cathodic protection, metallic zinc coatings, bonded dielectric coatings, dielectric coatings with cathodic protection, and trench improvement. Detailed information on these methods of protection are available from other sources and are beyond the scope of this guide.
1.3The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.4This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.