Pipeline Testing.docx

PIPELINE TESTING Testing of Sewers Cleansing of Pipelines On completion of construction, internal surfaces of pipelines shall be cleaned thoroughly. Precaution Prior to Testing Pipelines Before testing any pipeline, the Contractor shall ensure that it is anchored adequatelyand that thrusts from bends, branch outlets or from the pipeline ends are transmitted to solid ground or to a suitable temporary anchorage. Open ends shall be stopped with plugs, caps or blank flanges properly jointed. Suitable water shall be used for the cleansing, testing and swabbing of pipelines unless otherwise directed by the Engineer. Stand pipes for extracting water from the public supply system shall be in accordance with the requirements of the supply authority. As a minimum a check valve system shall be provided between the public supply and the item being filled to prevent the possibility of back siphonage. The Contractor shall provide all labor, testing equipment (including additional pipework jointing material, stoppers, and blank flanges) and shall fill the pipes with water and subsequently empty them after test, all to the approval of the Engineer. Water drained from the pipes shall be discharged in a way that does not affect the stability of the Works or adjacent structures. Testing Method Program and Notification Before any testing of a pipeline, the Contractor shall submit to the Engineer his proposed program of testing and, where required, swabbing. The Contractor shall notify the Engineer at least 3 clear working days beforehand of his intention to test a section of pipeline. Testing The testing of sewers shall include (1) tests for straightness and obstructions; (2) checks on infiltration and (3) tests for water tightness. The Contractor shall provide, at his own expense, all equipment, labor, materials and water necessary and carry out the prescribed testing. Tests for straightness and obstructions and checks on infiltration shall be performed on sewers and manholes. Tests for water tightness shall be performed on finished section of works prior to connecting existing collectors that are in function and will be connected in future; Tests for Straightness and Obstructions Visual tests for linearity and freedom from obstructions shall be carried out after completion of the works and be performed by means of a lamp and mirror. Invert levels of the sewers and inspection chambers shall be tested and verified with levelling instruments. Checks on Infiltration Infiltration checks shall be performed when backfilling is completed and all inlets to the length of sewers under testing have been effectively sealed. Visual inspection will be performed in sections of interceptor determining the degree of infiltration which must meet the relevant values regarding the standards and norms. Manholes and inspection chambers will be visually inspected for water tightness against infiltration after backfilling has been completed and groundwater table is at is highest level. Under these conditions no visible infiltration flow shall be admitted.

Testing Non-Pressure Pipelines Sewer pipes laid in open cut shall be tested with air or water (as specified below) after they have been bedded and jointed and before any concrete surround or backfill is placed, other than such as may be necessary for structural stability whilst under test. The pipelines shall be tested in lengths applicable to the construction activities and in accordance with the program. A further test shall be carried out when any concrete surround has been completed and when backfill has been placed and compacted to a depth of 300 mm above the crown of the pipeline. Tests for Water tightness Sewer shall be tested for water tightness by means of hydrostatic testing. Hydrostatic testing shall be applied after partial backfilling. Testing shall be carried out from manhole to manhole. Short branch laterals connected to the sewer may be tested as one system with the sewer. Long branches and manholes shall be separately tested. The hydrostatic testing shall be carried out as follows: (a) After completing the installation and covering of a sewer line or a section of the line, hydraulic testing of the line shall be performed, when directed by the Engineer. The test pressure shall be 1.0 m head of water at the highest point of the section under consideration. (b) At the upper end of the sewer a gauge glass shalt be connected to the sealing plug to enable the observation of the water level during the test. The gauge glass should have an inner diameter of approx. 50 mm and shall be provided with a mark located 1.0 m above the top of the sewer. An air vent and a cock should be installed at the same end as to allow for the release of air during the filling of water for testing. (c) The pipe shall be filled with water for a period of minimum 2 hours and maximum 24 hours before testing in order to allow for an adequate soaking period and the complete release of air. The water level shall be kept at the mark of the gauge glass during the entire soaking period. The hydrostatic test shall be carried out immediately after the soaking period. (d) The leakage of the pipe is defined as the quantity of water which must be supplied to the pipe during 10 minutes to maintain the specified water level. The additional quantity of water filled into the pipe shall be measured with an accuracy of 0.1 liters. (e) The sewer will be accepted in respect of water tightness if the quantity of water added during 10 minutes is in accordance with the norms and standards.

Air Test for Non-Pressure Pipelines Pipelines to be air tested shall have air pumped into the length under test until a pressure equivalent to 100 mm of water is indicated on a U tube gauge connected to the system. The pipeline shall be accepted if the air pressure does not fall below the value specified in the testing program. 1.12.7.8 Testing of Pressure Pipelines (Thermoplastic Pressure Pipelines) Pressure pipelines in their entirety (including all specials and valves) shall be pressure tested. Pipes shall be filled with water and tested in sections of convenient lengths, which must not exceed 1000 meters. Where pipes are laid with steep gradients the length of pipes tested at any one time shall be as directed by the Engineer. Gauges used for testing pressure pipelines shall be capable of reading increments of 1 m head. The Contractor shall be responsible for the independent calibration of the gauge prior to commencement of testing. The ends of pipes under test shall be closed by means of caps or blank flanges with anchors all provided by the Contractor. Valves must not be used for this purpose. All scour valves and air valves shall be replaced by blank flanges before commencement of the test. The pipe shall be slowly and carefully charged with water until the specified test pressure is reached in the lowest part of the section. Pipes internally lined with mortar shall be allowed to stand full for at least 24 hours before testing. The test pressure shall be maintained, by pumping if necessary, for a period of one hour. The pump shall then be disconnected, and no water addition shall occur, for a period of one hour. At the end of this period the original pressure shall be restored by pumping and the loss measured by drawing off water from the pipeline until the pressure as at the end of the test is again reached. The test pressures, unless otherwise specified, shall be 1.5 x the maximum working pressure.

The pipeline shall be accepted if the loss does not exceed values in norms and standards. During the test the pipe joints shall be inspected for leakages. Shall leakage of water occur at the joints, the joint shall be reassembled to eliminate such leakage or, shall this not prove possible, the Contractor shall supply and assemble new joints at his own expense. Thermoplastic Pressure Pipelines Testing of thermoplastic (PVC, polyethylene) pipelines shall be carried out generally as specified above, together with the procedure as detailed below to take into account of the viscoelastic (creep) response of the material. The procedure shall be as follows: • When the main is fully charged and all air vented, the system shall be allowed to stabilize before the test procedure begins • Pressure shall be applied at a constant rate and the time tL taken from the start of pressurization to attainment of test pressure must be recorded. • Readings of pressure decay at time intervals in minutes must be taken and recorded. • The first such reading P1 is taken at any decay time t1 equal to and greater than tl • The second reading P2 is taken at any decay time t2 equal to and greater than 5 x tL • Calculate N1;:: (loge P1 - loge P2) I (loge t2 - loge t.) which shall be between 0.04 and 0.12. If N1 is greater than 0.25, then an unacceptable leak is indicated. • A third reading P3 is taken at any decay time t3 equal to and greater than 15 x tL • Calculate N2 = (loge P2 - loge P3) / (loge t3 - loge t2)' If N2 is greater than 0.25, then an unacceptable leak is indicated. If the ratio N1 I N2 is less than 0.8, an unacceptable leak is indicated. Repairs and Making Good of Defaults Repair and making good of defaults observed after testing includes, as directed by the Engineer, the correction of alignments and levels and the properly fixing of any two pipes. Brushing, grouting, cementing or concreting of pipes is not allowed, neither before nor after running the tests. All necessary repairs, re-testing and replacement ordered by the Engineer shall be at the Contractor's expense. If the linearity of a sewer line between two manholes is not given, the Engineer may order to dismantle and relay the pipe or to arrange for an additional manhole at the bending ensuring the linearity between two neighboring manholes. Should the losses in any line tested exceed the permissible leakage by more than 5 %, the Contractor shall, after repairing and making good any leaks, carry out further tests to prove evidence of the permissible leakage rate. The above procedure shall apply also for lines and house connections which are to be tested after backfilling, hereby a tolerance of 15 % from the permissible leakage rate infiltration shall be allowed. Testing and Disinfection of Water Pipelines General All pipelines and all water retaining works shall be subject to pressure and leakage tests after being laid and installed but before commissioning. Pressure and leakage tests shall be carried out simultaneously. Flushing of Pipelines Before any water tightness test at pressure and non-pressure pipelines commences, the pipelines shall be cleaned by flushing, pigging or swapping. All flushing, pigging and swabbing shall be included in the unit prices for pipe installation and repetitions of the procedure shall be entirely at the Contractor's expense. It is therefore in the Contractor's interest to maintain the cleanliness of the pipe during and after installation. Testing of Pressure Pipes Ductile cast pipelines shall be tested according to DIN EN 805. HOPE pipelines shall be tested according to DIN V 4279-7. The Contractor shall be responsible for the supply of water for pressure testing. Water for disposal must be channeled to the nearest available watercourse/storm water drainage system as approved by the Engineer. The Contractor shall provide all test rigs, temporary blind flanges, gauges, pressure raising equipment, pressure recording instruments and all other necessary equipment to satisfactorily carry out the tests as specified in this Requirement. The Contractor shall further supply all labor and supervision needed for the performance

of the tests and recording the results. All gauges and equipment are to be submitted for approval to the Engineer. All test gauges shall be dead weight tested and proved at the commencement. Should any section fail to pass the tests, the Contractor shall determine the cause of the failure and shall locate, excavate and repair any damage or leakage sustained by the pipeline before or during the tests, and retests the section. The cost of such repair work, including (but not limited to) additional excavation and backfilling; repair or replacement of pipes; and the abortive test shall be borne by the Contractor. A certificate shall be signed by the Engineer and the Contractor and the chart of the test attached. This certificate shall be produced when applying for Taking Over of any particular area. This documentation shall be prepared by Contractor and comprise all relevant information. No visible sign of leakage will be accepted. If a leak occurs in the pipeline it shall be located and shall be made good by the Contractor at his own expense before restarting the test. If the calculated leakage rate is within the allowable leakage rate, the test water shall be transferred to the next section of the pipeline to be tested or disposed of as approved by the Engineer. Air tests shall not be permitted. Where a new pipeline is to be connected to an existing pipeline, the new pipeline shall be tested up to the point of connection. After testing the connection shall be made up and left exposed for visual inspection by the Engineer. On completion of testing, and if initial sterilization as specified is successful. The section of pipeline shall be properly sealed to prevent the intrusion of any extraneous matter until connected to the pipeline network. Only the VIKS's staff shall operate their own valves where necessary, and the Contractor shall provide the Engineer with a minimum of 2 days’ notice so that the appropriate attendance can be arranged. It shall be the responsibility of the Contractor to obtain any water or other services required for test purposes and pipe it from the supply point to the filling point on the system, and to dispose of any such water after testing in a manner acceptable to the Engineer. Testing - Plumbing Systems The hydraulic test pressure of plumbing systems shall be 1.5 times the maximum working pressure for a period of 30 minutes. In addition to the above the equipment shall be inspected and tested after erection. Project title: Water Supply and Sanitation Adrialic Coast lll - Bar Project number: BMZ ID 2006 66 196,200765479 project number Vodacom: RB·8R·2oo9

100 WATER SUPPLY AND SANITATION ADRIATIC COAST III • BAR VOLUME III - TECHNICAL SPECIFICATION - SECTION 3.2 CIVIL WORKS

On completion all plumbing systems shall be flushed out with clean water and then subjected to a hydraulic test of 1.5 times the working pressure for a period of not less than 30 minutes. All welds shall be hammer tested and remain firm. A normal working test shall then be carried out with the plant operating temperature. During this test all necessary adjustments and regulations of valves shall be effected. Installations or sections thereof which will be embedded in the structure or concealed in permanently sealed ducts, trenches etc. shall, in addition to the above specified tests be individually tested as they are laid before being embedded or concealed. All pressure tests specified above shall be carried out before the application of thermal insulation. 1.13.20.5Disinfection On completion of the hydraulic test on water mains, a total clean water shall be passed through the main for final cleansing sufficient times. The Mains and reservoirs shall be disinfected with adequate chlorine solution according to procedure approved by Engineer. The Contractor shall obtain the Engineer's approval of the method to be adopted for disposing of the chlorinated water and then time when such disposal shall take place on completion of the disinfection .