1. Gravity pipelines laid in open cut shall be tested after they are jointed and before any concreting or backfilling is commenced, other than such as may be necessary for structural stability whilst under test.
2. The pipelines shall be tested by means of air and by a visual examination, in lengths determined by the course of construction. Generally pipelines will be tested as complete lines or between manholes.
Visual examinations shall be done by mirror and light, in which case, deviation of plus or minus 20mm, i.e. for 160mm and 200mm pipelines a 75% and 80% clear gauging is required.
3. A further air test shall be carried out after the backfilling is complete. Failure of this test may require a water test.
4. Engineer shall arrange for CCTV survey of lengths of sewers.
This survey may be done following completion of certain sewer lines and/or will be done prior to the end of the defects correction period. Should however the inspection of the selected pipelines fail, the Contractor shall first rectify the faults and subsequently arrange for hire of equipment and personnel to repeat the tests and for the survey of any other lengths.
The process shall be repeated at the Contractors expense until satisfied that the whole of the works is constructed in accordance with the drawings and the Specifications.
5. A pipeline shall have failed the CCTV inspection if any of the following are identified:
· Any evidence of cradling of the pipes;
· Any evidence that the pipeline is out of tolerance (e.g. depressions with ponded water, bends in the sidewall);
· Any dislocated or damaged joints;
· Any evidence of infiltration;
· Any projecting connections.
No comments:
Post a Comment