Study on improvement of hydrostatic testing method for long-distance and super-large diameter PCCP pipeline

The hydrostatic testing for validating the design operation conditions of the pipeline with all of the auxiliary structures is an item that must be performed before the completion acceptance of a pressure pipeline.For a long-distance and super-large diameter PCCP pipeline,the relevant testing requirements listed in the criteria concerned are difficult to be met,as the restrictions from the construction conditions of water source,construction period,backrest,etc.Based on the analysis of the hydrostatic testing requirements in various criteria,the necessity of the improvement of the testing method is expatiated herein,and then the improved method designed for the PCCP pipeline of the South-to-North Water Transfer Project is described from the aspects such as strengthening the sectioning of pipeline pressure in the prophase of construction,the arrangement of the maintenance facilities,the design of the tightness testing on the joints of the pipeline,the strict control of the manufacture of the pipeline,the tests related to the installation,etc.