发布时间 : 星期二 文章Procedure for Cleaning,Flushing,Gauging and Hydro Testing of Pipelines更新完毕开始阅读643226a6a58da0116c17499c
East-west Gas Pipeline Project Construction Procedure for Cleaning, Gauging And Hydro testing of Pipelines Rev.: A1 China Petroleum Pipeline Bureau（CPP） Document No.: EWPL00-COS-PR-0014 6.5.7 Emergency measures for the failure of pigging Failures Causes Measures 1. After depressurization, open the quick The air displacement of 1. The pig is not the pig at the receiving properly installed; end is large, and the pig stops traveling or 2. The pig is damaged on the way. again. 2. After depressurization, put in new pig and restart cleaning. 1. Raise air pressure (maximum not more than 1.6MPa) to push out the pig and then launch another pig equipped with a tracer. Find out the sticking point and cut off the The pig is stuck, there is The no air displacement at deformation pipeline pipe to take out the stuck pig. is 2. Move the air compressor to the other end closure to check if the pig has been sent out. If not, place the pig correctly and launch travels slowly the receiving end or the oversized or there may of the section, launch a pig with a tracer in air displacement is be some larger matter the opposite direction. Find out the sticking in the pipeline. point and cut off the pipe to take out the stuck pig. The operation of pipe cutting off, assembling and welding again shall be in accordance with the pipe welding procedure, Doc. 6.6 Operation process of pipeline section gauging inspection 6.6.1 Gauging
The operation of gauging inspection is carried out after the completion of cleaning.
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small. East-west Gas Pipeline Project Construction Procedure for Cleaning, Gauging And Hydro testing of Pipelines Rev.: A1 China Petroleum Pipeline Bureau（CPP） Document No.: EWPL00-COS-PR-0014 The pig traveling speed will be kept about 5km/hr. In order to obtain a proper traveling speed, during the operation of pigging for the uphill sections, the valve L02 fixed on the receiver shall be in close position until the pressure in front of the pig is higher than 0.5barg; for the downhill sections with hot bends, back pressure shall be built up to 2barg. In addition, the pressure behind the pig will be no higher than 2.5bar(g) that will be obtained by reducing air input to the pipeline. This can be achieved by adjusting the relief valve fixed at the outlet of the air compressor. Other operating procedure of pigging for gauging inspection is the same as cleaning, for details please refer the description above.
The gauge plates shall be examined immediately by the Engineer-in-Charge and CONTRACTOR?s test engineer when the gauging pigs arrived.
Photos will be taken for recording the conditions of the gauge disks after gauging operation. All records will be witnessed by the Engineer-in-Charge and be included in the final report.
The temporary launcher and the receiver will be removed if gauging inspection has been checked and accepted by the Engineer-in-Charge, and then preparations for water filling will be carried out. Otherwise the cause of the failure will be analyzed and the solutions will be determined by the Engineer-in-Charge and the test engineer. Remedied for the failure of gauging inspection will be undertaken by CONTRACTOR.
After the completion of pipeline section gauging, pipe caps will be adopted to cover both ends of the pipeline sections.
6.6.2 Gauging Records
All gauging operations will be recorded in tables with the following data.
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Type(s) of the gauging pig Type of the driving media Time of launching and receiving
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East-west Gas Pipeline Project Construction Procedure for Cleaning, Gauging And Hydro testing of Pipelines Rev.: A1 China Petroleum Pipeline Bureau（CPP） Document No.: EWPL00-COS-PR-0014 ? Photographic record of the conditions of the gauge disks after use All records shall be witnessed and confirmed by both CONTRACTOR?s test engineer and the Engineer-in-Charge and shall be included in the final report. 6.6.3 Checking and acceptance
Gauging inspection is deemed acceptable if no dents, bends or large gouges are apparent on examination. 6.6.4 Measures for the failure of gauging inspection
If dents, bends or large gouges are found on the gauging plate, the following methods will be used to solve the problems:
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Send another gauging pig to determine whether the pipe section is deformed under the conditions of ignoring other factors, such as the deformation of the plate arisen from collision with the quick closure when the gauging pig enters into the receiver. ?
Check all the construction records of the pipeline installation. If any doubtful thing is found that may cause gauging inspection unacceptable, find the constructors who have participated in the operation at the time for clarifications. If possible, manual excavation will be carried out to find out the solutions and another gauging operation shall be taken. ?
If the method above does not work， check the air flow rate and pressure records of the gauging pigs carefully, the location where problem may exist can be predicted, send another gauging pig fitted with a pig tracer， check carefully for the location where the faults may exist. Manual excavation will be carried out to find out the faults, and then continue the gauging operation.
? If the above-mentioned methods do not work, inspect the pipeline with a caliper pig. First fill compressed air with certain pressure (2.0~5.0barg) into the pipeline with an air compressor. Then use the air compressor to send out the caliper pig through the temporary pig traps. Control the traveling speed of the caliper pig by monitoring the control valve at the receiver. Manual
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East-west Gas Pipeline Project Construction Procedure for Cleaning, Gauging And Hydro testing of Pipelines Rev.: A1 China Petroleum Pipeline Bureau（CPP） Document No.: EWPL00-COS-PR-0014 excavation will be carried out after the examination and setting the location, determine the solutions and continue the gauging inspection. 7.0 PIPELINE SECTION HYDROSTATIC TEST
7.1 General
Hydrostatic test will commence after section cleaning and gauging as well as confirmed by the Engineer-in-Charge. This procedure is intended for hydrostatic test of the pipeline trunk, not for PTS, LVS and so on. The length of test section basically will be the distance between two line valve stations or a line valve station and the nearby pig trap station.
7.2 Test section
The length of the test sections basically will be the distance between two line valve stations or a line valve station and the nearby pig trap station (not exceed 50km).
As LVSs have been installed before hydrostatic test, test ends are about 95m away from LVSs. The main lines will be cut off and test heads will be installed locally.
Test section data of spread 5 and spread 6 are shown as below. TEST SECTION 1 2 3 4 5 6 7 FROM TO LENGTH TEST km 651.909 683.83 709.508 738.353 773.447 802.65 838.239 km 683.83 709.508 738.353 773.447 802.65 838.239 861.127 km 31.92 25.68 28.84 35.09 29.20 35.59 22.89 SECTION 8 9 10 11 12 13 FROM TO LENGTH km 861.127 892.392 918.71 948.808 976.4 999.152 km 892.392 918.71 948.808 976.4 999.152 1025.5 km 31.27 26.32 30.10 27.59 22.75 26.35 Page 24 of 56