This standard covers installation procedures for ductile-iron mains and their appurtenances for water service. 1.1.1 Conditions not covered. Installations that require special attention, techniques, and materials are not covered. Each such installation requires special considerations based on many influencing factors and cannot be covered adequately in a single standard. This type of installation can best be accomplished by a competent engineering design in consultation with representatives of the material manufacturing industry. Some of these installations include the following: Piping through rigid walls; Piping on supports above or below ground; Piping requiring insulation; Treatment plant or pump-station piping; Industrial piping; Piping through geologically hazardous areas; Piping in high-density-stray-current environments; Piping through corrosive soil; and Piping through unstable soil. Major changes made in this revision of the standard are as follows: Nominal 60-in. and 64-in. diameter pipe have been added; Information on unloading pipe has been added (Sec. 2.2.1); A section has been added referring to AWWA Manual M27, External Corrosion--Introduction to Chemistry and Control (Sec. 3.3.9); Information on transition couplings has been added (Sec. 3.3.10); A recommendation on gauging pipe selected for cutting has been added (Sec. 3.4.4.4); A new diagram (4) has been added to Figure 2; Section 3.7 on hydrant installation has been substantially revised; A precautionary statement on preventing contamination at cross-connections has been added to Sec. 5; A new section on sub-aqueous crossings has been added (Sec. 7); A recommended procedure for making service taps on polyethylene-encased iron mains directly through polyethylene tape and polyethylene film has been added to Sec. 8.1 (previously Sec. 7.1); and Terms defining contractual parties (owner, contractor, and so forth) have been deleted from the standard, and Sec. II.A, Supplemental Information Required for Use of This Standard, has been added to the foreword.