Untitled - Future Pipe Industries

More documents

Recommendations

Info

7.2: Bracing test-ends and set-up Due to the thrusts occurring at the testing end-caps, temporary blocks must be used to brace the pipe end-caps in order to prevent line displacement as indicated in the figure 24. Figure 24: Thrust blocking pipe ends and site pressure test set up In the gap between the end of the pipeline and the block, jacks should be placed as shown in figure 24. This will keep the testing end cap at its original position if the block starts to move. The last pipe length should also be wedged on both sides, at the top and at the bottom, in order to prevent lateral and vertical movements. Sandbags can be used for this purpose. Note: It may be possible to reduce the size of the concrete blocks by driving into the ground, several meters deep, two or more steel sheet piles back to back. Sheet piles so positioned behind the concrete blocks will provide additional bracing. 7.3: Filling the line with water If it is not possible to fill the line from the lowest point, an additional outlet should be added at the inlet end-cap to release air. The line should be filled slowly and evenly with water from the lowest end point. At high points, an automatic air release will normally be installed, as specified by the design Engineer (see appendix II for additional details). Through these valves, the entrapped air will be released. After filling the line with water, the test section should be left for an initial period of at least 12 hours under a low static pressure of 30 psig for stabilization. The filling rate of the line with water should be controlled such that the water velocity does not exceed 1 ft/second. Following the stabilization period and after expelling all the entrapped air out of the pipe test section, the release valves should be closed (isolated). 37
7.4 Volume of water required Table 13 indicates the approximate volume of water required in order to fill pipes per 100 feet of pipeline. DN Inch Water volume (gal) / 100 ft of pipeline 3 39 4 69 6 154 8 270 10 430 12 615 14 840 16 1,100 18 1,390 20 1,700 24 2,450 28 3,350 30 3,850 33 4,700 34 4,950 Table 13 7.5: Initial test (method 1) After the test section is ready, the line shall be filled with water and kept under low pressure (30 psig) for at least 12 hours to allow the pipeline to stabilize and to release the entrapped air from the line. After the stabilization period, the pressure shall be raised gradually at a rate of 15 – 30 psi every half an hour, until the intended test pressure at the lowest point is reached. Unless otherwise specified by the Engineer, the test pressure shall be equal to 1.5 times the intended working pressure of the pipeline section. Once the required test pressure is reached, the pressure should be maintained for one hour, by pumping if necessary. The pump should then be disconnected and no further water permitted to enter the pipeline section for one hour. At the end of this one-hour period, the original test pressure shall be restored by pumping water from a graduated water tank and measuring the amount of water necessary to restore the test pressure. Unless otherwise specified by the Engineer, the test water loss should not exceed .03 US gallons / inch of diameter per mile of pipeline per 24 hours per psig of test pressure applied (average test pressure of section). This is equivalent to 4.5 gpd / mile / inch for a 150 psig test pressure. During the pressure test, all joints should be visually inspected (where possible), and all visual leaks should be repaired. In case the test in not satisfactory, the locations of the leaks shall be determined and rectified, and the line re-tested in the same manner as shown above. The test section shall be accepted only after successfully passing the above leakage test. Note: The Contractor should note that while pressure testing large diameter pipe on site at pressures generally above 150 psi, there is a possibility of a slight rotation/pivoting of the Reka coupling. This is the result of uneven pressure against the various parts of the coupling, and is inevitable during normal joint assembly where a perfectly centered and aligned joint can never be achieved. In the unlikely event that one or more joint starts to rotate or to shift slightly during the pressure test, it is advisable to reduce the pressure, and to backfill the joints completely using selected, properly compacted backfill, prior to resumption of the pressure test. Any joint that has shifted significantly should be centered again before resuming the pressure test. 38 DN Inch Water volume (gal) / 100 ft of pipeline 36 5,550 42 7,500 48 9,900 54 12,500 60 15,400 72 22,200 80 27,500 96 39,500 108 49,950 114 55,650 120 61,700 132 74,500 144 88,800 158 107,000
Page 2 and 3: All information was correct at the
Page 4 and 5: 1.0: Introduction This manual deals
Page 6 and 7: 2.5: Storing pipes on site 2.5.1 Di
Page 9 and 10: Figure 4: Pipes in the same trench
Page 11 and 12: 4.0: Backfilling and installation s
Page 13: 4.5: Classification of native soils
Page 16 and 17: Installation type I ASTM D1586 Blow
Page 18 and 19: Installation type I ASTM D1586 Blow
Page 20: Installation type I ASTM D1586 Blow
Page 23 and 24: 5.1.1: Joint lubricant For lubrican
Page 25: Mechanical lowering is used for lar
Page 28: 5.6: Pipes with locked joints For s
Page 31 and 32: Caution: Always provide a standard
Page 34 and 35: Figure 20 6.2: Pipe zone backfillin
Page 36 and 37: 6.3: Backfilling where temporary sh
Page 38 and 39: 7.0: Hydrostatic testing of pipelin
Page 42 and 43: 7.6: Final pressure test After all
Page 44 and 45: 7.9.2: Low head water test The Cont
Page 46 and 47: 9.0: Tapping water mains Pressure p
Page 48 and 49: APPENDIX II: Design considerations
Page 51 and 52: APPENDIX III AIR IN PIPELINES, AIR-
Page 53 and 54: APPENDIX IV FLANGE INSTALLATION INS
Page 55 and 56: Table 1a If connected to raised fac
Page 57 and 58: APPENDIX V: LIST OF REFERENCES The

Untitled - Future Pipe Industries

Create successful ePaper yourself

Delete template?

Save as template?