Page 182 - Water Standards
P. 182

ping.
                             3) The technology requirements for steel pipe installation shall
                                 meet the requirements in Article 5   1   17 of this specifica⁃
                                 tion.
                       3   8   4  Exposed steel pipe construction shall meet the following re⁃
                       quirements:
                           1  The excavation of the steel pipe line shall meet the require⁃
                       ments in Article 2   3   2 of this specification. The pipe trench shall be
                       excavated with pre⁃splitting blasting. Loosing rock shall be cleared.
                       Drainage system shall be carried out and slopes shall be treated.
                           2   The construction of anchorage blocks and supporters shall
                       meet design requirements, and also meet the requirements in Sections
                       2   7 and 2   8, and Article 2   3   2 of this specification.
                           3   The procedure and requirements for steel pipe installation
                       shall meet the following provisions:
                             1) During the process and installation of pressure steel pipe,
                                deformation or damage shall be avoided.
                             2) The right installation procedure shall be selected. The el⁃
                                bows shall be fixed first, and then according to the
                                position of the expansion joints, installation from bottom to
                                top (when the expansion joint is close to the downstream
                                side of the anchorage block), or in upstream and down⁃
                                stream directions ( when the expansion joint is between
                                two anchorage blocks).
                             3) Steel pipe temperature shall be timely measured during in⁃
                                stallation, and based on this, the surplus length of the
                                expansion joint is correctly determined.
                             4) Longitudinal seams of adjacent pipe sections shall not be
                                arranged the same straight line.
                             5) Cableway or flat rail wagons can be used to transport steel
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