This standard has been prepared so that design engineers may determine the correct pressure classification of asbestos cement transmission pipe to use under various combinations of internal pressure (static, operating, and surge) and external load (earth and superimposed live loads). Combined loading curves depicting the relationship between hydrostatic loading and external loading capabilities are included to expedite the selection of the correct pipe strength classification. Information to assist the engineer in selecting the most economical size of pipe is in the appendices. Section 1 discusses scope, purpose and application. Sections 2 and 3 lists references, definitions, symbols, and abbreviations. Section 4 discusses permeation, pressure classes, installation, general design, external loads, hydrostatic pressure, design criteria and use of pipe selection charts. Appendix A contains a friction loss of head chart based on the Hazen and Williams formula. Appendix B is a detailed analysis of surge pressure factors. Appendix C includes tables to assist the engineer in determining yearly power costs to overcome loss of head due to friction. The major revisions for this edition of ANSI/AWWA C403-95 include the following: the format has been changed to AWWA standard style; an acceptance clause (Sec. I.C) has been added to the forward; Section II, special issues, was added to the forward. This section now includes a discussion on criteria for selecting the type of asbestos cement pipe.