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 following is a sketch indicating the installation of the temporary pig traps as well as the equipment and devices for the operation of cleaning and gauging. The dimensions of the pig launcher and receiver are for 48”. air compressor control valve(throttling valve)DN114×7quick closurepressure gauge
Figure-4
The connection between the temporary pig traps and the pipeline trunk as well as the test pipes and fittings will be welded according to EWP100-P30-J00-505 Specification for Pipeline Welding .
After the installation and before the pigging operations, operators shall check that all equipments and devices are in good condition and well functional for pigging activities. 6.3 Safety and protecting measures
Protecting fences around the area near the pipeline end will be provided if necessary.
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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 Bulletin boards shall be placed beside both ends of the pipeline being tested, notifying that it is high dangerous near the pipeline end. Warning massages warning: dangerous area, keep out shall be printed in red color, and in three languages: English, Chinese and Indian. All warning notices, marker tapes, protective fences and other safety equipment shall be taken away after the completion of pigging.
During the whole pigging process, two person will be assigned to each side of the test section to keep watch that no one will be near the end of the pipeline trunk being tested. 6.4 Confirmation Prior to Cleaning and Gauging
A pre-test check shall be performed before pigging is commenced. The check-list shall include checks to confirm that:
? The request for pipeline section pigging and gauging has been approved by Engineer-in-Charge
? All the temporary pig traps, pipe fittings and other equipment or devices connected to the test section have
been checked by the operators, they are in good condition and well functional for pigging activities. ? All instruments and gauges to be used for pressure testing have been calibrated and valid test certificates
have been approved by the Engineer-in-Charge
? All warning notices, marker tapes, protective barriers and other safety facilities have been positioned. ? The communication facility have been established and tested and is available. ? The personnel engaged in the testing work are clear about the emergency plans. 6.5 Operation process of pipeline section cleaning 6.5.1 Cleaning
The following procedures will be carried out for pipeline cleaning pigging. The below description will refer to Figure 4.
6.5.2 Positioning the pig and checking before launching
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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 Open the quick closure behind the pig launcher and put in a cleaning pig. The pig shall be placed into the neck of the launcher and the interface between the neck and the first cup on the pig shall be as tight as possible, and then close the quick closure.
6.5.3 Launching and running the pig Start up the air compressor to send the pig. The pig traveling speed will be kept about 5km/hr.
Two operators will monitor the pressure gauges and valves fixed on the launcher and the receiver continuously. The operators shall immediately report to the Test Engineer any apparently variation which may result in failure. For detailed information about the failure and the measures, please refer to Emergency measures for the failure of pigging describe below.
The following method is intended for locating traveling pigs.
During pigging operations, location of the pig will be calculated approximately by measurement of the volume and pressure of the driving medium. The following formula will be used to determine the pig approximate location.
L=where
vtS e L: distance from the pig launcher to the traveling pig, m v: the capacity of the air compressor, Nm/h
3
t: traveling time of the pig, hour
S: inner sectional area of the pipeline, m
e: non-dimensional coefficient which is the multiple number of the pressure behind the
traveling pig to the atmospheric pressure
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2
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 6.5.4 Receiving the pig An operator shall inspect the sign continuously when the pig is predicted to arrive. Full open valve L01 and L02 to depressurizing as soon as the pig?s getting into the receiver is confirmed. After the pressure inside the pipeline drops to the atmospheric pressure, open the quick closure and take out the pig. 6.5.4 Measuring and recording
The quantity of the debris and deposit in front of the pig will be measured and recorded immediately.
Pigging for cleaning will be continued till the volume of the received materials by the last pig is less than 5 liters. The preparation for pipeline section gauging pigging will be made after the Engineer-in-Charge confirmation that the pipeline cleaning is acceptable. 6.5.5 Pigging records
All pigging operations will be recorded in tables with the following data.
? ? ? ? ?
Number of the pig run Type(s) of the pig Type of the driving media Time of launching and receiving
Volume and nature of material and substances arriving in front of the pig at the receiving end
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. 6.5.6 Checking and acceptance
Pipeline cleaning is deemed acceptable if the volume of the received materials by the last pig is less than 5 liters.
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