CITY GAS DISTRIBUTION PRESENTATION(CGD).pptx

City Gas Distribution(CGD) networks are an interconnected system of underground Natural Gas pipeline for supplying Piped Natural Gas (PNG) and Compressed Natural Gas(CNG) to domestic ,commercial and industrial customers.

1. CITY GAS DISTRIBUTION(CGD) Laying Testing and Commissioning of Coated Steel Pipeline (Associated Civil and Structural Work and Installation of Skid) for CGD Project

2. City Gas Distribution(CGD) networks are an interconnected system of underground Natural Gas pipeline for supplying Piped Natural Gas (PNG) and Compressed Natural Gas(CNG) to domestic ,commercial and industrial customers. TITLE

3. Survey, ROU Cleaning and Grading Stringing of pipes Trenching Mainline welding Radiography Inspection by X-ray Repair welding Tie-in welding SEQUENCE OF WORK

4. Field joint coating Backfilling Pre Hydro Testing Final Hydro Testing HDD Crossing Pre commissioning Commissioning Cont..

5. To indicate the pipeline route at site including the ROW limits, pipeline alignment, pipeline chainage, crossing limits, identifying the existing pipeline in common ROW, Cleaning & Grading etc. in accordance with the route maps and crossing drawings of CGD Pipeline Project . REFERENCES & EQUIPMENTS Route Maps Alignment Sheets Excavator Tractor Rock Breakers Grader Tipper / Tractor Mounted Compressor, DG Survey ,ROU Cleaning and Grading

6. This work involves laying out the pipe segments along the ROW for mainline welding during the execution of pipeline project. EQUIPMENTS : Pipe Layer/Crane/Hydra Trailer Rigging tools i.e., Sling, Nylon rope, Nylon belt, Clamp (with Teflon pad to protect bevel end of pipe) MANPOWER : Pipe Layer/Hydra Crane Operator Supervisor Riggers Helpers Trailer Driver The fitness certificate of equipment's shall be available at site. Stringing of pipes

7. The content of this procedure covers the work of creating a narrow excavation on ROU below the surface of the ground by using an earth moving machine. EQUIPMENTS Tractor mounted Rock Breakers (If required) Excavators Dumpers Tractor mounted trolleys Pickets and other hand tools Cable & Pipe Locator (if required) Any other equipment required for complete this job. Trenching

8. All work shall be carried out as per approved procedures/drawings Need to be take permission to related authority or concerned party for remove (temporarily) or shifting of cables, pipeline, poles or pylons, for carry out the work with professional and experienced personal. No blasting is allowed within 15m of any existing pipeline or structures (either above or below ground ) Fresh excavated soil should not be mix with foreign material, loose debris etc . After excavation near to crossing, area should be proper barricaded and use the reflected sign board for night purpose. Trenching methodology

9. Mainline welding also known as girth welding, the procedure involves pipeline welding is a type of fabrication process used to assemble pipes and form a network. EQUIPMENTS Pipe Layer/Hydra Crane Welding machine Diesel Generator Set External Clamp with mechanical jack Beveling Machine Grinding Machine Welding Booth Hand Tools i.e. Chipping Hammer, Gloves, Welding Shields etc. Flame Heating Burner with LPG Cylinder Filler gauge Hi Lo gauge Welding gauge Clamp meter Thermo meter/Thermo pen The Calibration/fitness certificate of equipment's shall be available at site . Mainline welding

10. Each length of pipe shall be thoroughly examined internally and externally. To make sure it is free from visual defects, corrosion, dirt or foreign matter. Each pipe length shall be adequately swabbed to remove foreign matter and pulled through proper to ensure it is free from dirt before lineup. While using pull through proper care should be taken to avoid damage of coating before welding, all rust and foreign matter shall be removed from the beveled ends by power-operated tools The pipes shall be positioned on skids of height 500 mm from the ground, skids shall be at least 1.20 meters long and shall have a width of at least 200 mm, and such supports shall be minimum two per pipe and skid shall have soft pads placed over them to avoid damage to the 3LPE coating, Pipes shall be locked to prevent their rolling from the skids. The Root gap & Root face shall be checked accurately and shall be as per qualified WPS. Earthling clamp shall be used for connecting pipe to welding machine terminal Methodology

11. Welding shall be done as per the approved welding procedure specifications (WPS). Only qualified welders shall be engaged and each welder shall bear an identity card during welding operation. Pipe shall be heated using resistance or induction heating methods. Pre-heating by gas burners, utilizing acetylene or propane gas, LPG may also be carried out. Preheat temperature of at least 100º.C shall be maintained prior to commencement of root run and subsequent runs. Welder shall start from 12'O' clock position and proceed towards 6'O' clock position. Then Start from 9`O`clock position and proceed towards 6`O`clock position then from 12’O’Clock to 9 O’clock. Welder shall be overlapping the weld at 12 ‘O’ clock position Welder shall close by over-lap 6 ’O' clock position then close overlap 9 'O’ clock position. Every pass shall be cleaned by power-brush, grinding machine and chisel, starting and finishing points shall be staggered for every pass. Capping shall be max 1.6 mm over the surface of the pipe and shall not be less than 0.8 mm. Spatters shall be removed and cleaning shall be done by power brush and any remedial grinding necessary, shall be performed limited to dressing. Cont..

12. The purpose of this work instruction is to lay guidelines and requirements and to establish a method or a system to control the Manual Ultrasonic Test inspection activity and procedure is used to detect internal discontinuities of Pipes / Welds. This is a general procedure which describes Examination of weld of pipelines, by using Ultrasonic flaw detector with pulse echo contact beam method. Radiography Inspection by X-ray

13. X-ray Source with control units (X-ray Crawler/External X-ray Unit) with all arrangements Survey Meter Dosimeter Films loaded in Cassettes as per Requirement Lead Screen Warning Placards Cordoning Rope Crayon or Paint Markers Measuring tape Elastic Penetrameters (ASTM SET A/10 ISO 16) Lead Markers Dark Room Accessories & Consumables EQUIPMENT, CONSUMABLES & ACCESSORIES

14. All surfaces shall be clean and free of scale, dirt, grease, paint, spatters or any other foreign materials. Surface shall be smooth to carry out effective test. If surface is not smooth as reference block, db correction shall be done. The combination of probes in addition to normal probes shall be selected as per specific requirement or as per thickness of the pipe. Scanning by T-R probe for lamination. Hundred percent areas shall be scanned on both side of the welds using longitudinal and shear wave probes. Length of scanning shall be minimum of 1½ Beam Path on the both side of the weld. Unless otherwise specified, inspect the weld on both sides by using longitudinal & sheer wave probes. Methodology

15. All indications that are equal to or greater than rejection level, established during calibration, as described in acceptance / rejection criteria in section 15 of this procedure of agreed by client’s inspector, shall be considered representing defects and may be cause of rejection repair of the weld or base metal. Acceptance or rejection criteria shall be in accordance with API 1104 or as per specified in client’s specification. All defect location shall be Recorded & / or marked for repairing. Retest of the repaired area shall be carried out in accordance this procedure. Cont..

16. The content in this procedure is limited to remove the weld metal where discontinuities are beyond acceptable limit and to facilitate re-weld as per approved WPS, which shall be welded by qualified welders during execution of CGD Pipeline Project site. EQUIPMENTS DG sets Gas Burner Welding Generator Grinding M/c. SMAW Set Repair welding

17. With respect to radiography or other NDT method, location shall be marked on the weld with reference to marking of ref. Points (markers ). Partial repair (External): Each layer will be thoroughly checked for this type of discontinuity shown in NDT reports. Smooth grinding will be done to make ‘V’ Groove and clean all surfaces. This is limited to 30% of weld length only. Minimum 2 runs shall be made for partial repair. After cutting the repair area, ES shall be checked and ensure that the defect has been removed, by LPT on cutting area . Thru repair / Root Repair Grinding will be done up to the root, opening will be done by chisel, hacksaw blade. The entire vol. will be ground smoothly to ‘V groove, root gap will be achieved using blades, thin grinding wheels and filing. Maximum repair length is 20% of weld. The minimum length of a repaired area shall be 100mm as measured over the recapped length. Die-penetration test shall be done during and after removal of defective weld metal by grinding to ensure that the defect has been removed. After removing of the same, welding for repair should be carried out . Method of Evaluation

18. The process of connecting a new line or branch to existing line by means of cutting and welding new T shaped pipe spool with a valve on the hydrocarbon process line is called as a tie-in of pipelines EQUIPMENTS Hydra/ Crane Excavator Pipe- cutting (beveling cutter) Hand –cutting set NDT Crew (UT/LPT) External clamp – 18” φ Tie-in welding

19. The unconnected sections of the pipe line at various locations have to be tied in after the sections are coated, lowered and backfilled. The sections to be connected shall have at the ends, sections of over lapping, uncovered pipe of sufficient length to absorb, without inducing excessive stresses in the steel, small displacements necessary for perfect alignment and connection of the ends. The tie-in should be done in such a way as to leave a minimum of strain in the pipe. If necessary, with respect to the trench, realigning of the pipe shall be done to eliminate force or strain in the pipe by the ES . Field welding of pipelines TIE-IN joints shall be done by SMAW (Shielded Metal Arc Welding) process. Qualified welding procedures shall be used for welding of TIE-IN joints. Electrode starting and finishing points shall be staggered from pass to pass. For TIE-IN of adjacent sections of pipeline already pressure tested also called golden joints and for final joints, a single length pup or off cuts, which have been hydrostatically pre-tested shall be used. Methodology

20. T his procedure cover to install anti-corrosion field joint coating on welded pipe sections and field Tie-in Joints and to rectify joint coating repairs found during holiday inspection of welded pipe sections and field Tie-in joints EQUIPMENTS Compressor 125 cfm Hopper for sand blasting unit (To achieve SA-2.5 surface finish) Pump (Recommended by manufacturer) Blow heating Torch with gas cylinder Testing + inspection equipments /instruments Epoxy applicator pads Straight rollers / Teflon rollers Vehicle- tractor trolley Field joint coating

21. MANPOWER Blaster Qualified Insulator Supervisor Helper Driver   MATERIALS FOR FIELD JOINT COATING AND REPAIR: Heat Shrinkable Sleeves of Approved Vendor Primer Part A Type S1301 Primer Part B Applicator kits PERP 80 (for repair) PERP Filler / mastic filler INSTRUMENTS FOR FIELD JOINT COATING AND REPAIR : Digital Thermometer Hygrometer Coat Meter/Elko-meter Aluminum / rubber / Teflon hand roller Micrometer Press-O-Film/Comparator Holiday detector with 18” φ ring Portable Peel Tester Kit D.C. voltmeter (calibrated for holiday detector)

22. Prior to start of surface finishing or joint coating, the welded joint shall be cleared / accepted in NDT (RT/ UT) as per QAP . The wrap around sleeve shall be of a size such that a minimum overlap of 50mm is ensured (after shrinking) on both sides of the yard applied corrosion coating of pipe. Immediately after blast cleaning surface shall be wiped to remove the particles left over from cleaning . Pre heat joint area using blow heating torch to 70  C, ES shall ensure the correct temperature is reached on steel and line coating using a pyrometer. Apply mix (shall be with ratio 3:1 for part A part B) epoxy to a smooth finish on all exposed bare metal, including the line coating edge. Minimum wet film thickness for epoxy shall be maintained 100 microns. Flame of LPG torch shall be adjusted to produce yellow flame. Heat the closure evenly till the pattern of fabric reinforcement is visible. Run a small hand roller over the closure to push out any trapped air. Using LPG torches heat the sleeve, as recommended by manufactured circumferentially around the pipe beginning at the center using a roller up and down motion. Application Procedure of Heat Shrink Sleeves

23. T his procedure covers the backfilling of trench with the excavated/borrowed earth soil after providing soft padding/select backfilling as per requirements stated in alignment sheet & specification, and after slope breaker where shown in drawings EQUIPMENTS Excavator / JCB Equipment for laying of MDPE Hand tools like Shovels Etc. Tractor LCV PDG Backfilling

24. Backfilling shall not be done until the pipe and appurtenances have the proper fit and the pipe is following the ditch profile at the required depth that will provide the required cover and has a bed which is free of extraneous material and which allows the pipe to rest smoothly and evenly. Backfilling of trench in water courses shall be carried out as per the relevant specification issued for the purpose. Backfilling shall be carried out immediately after the pipeline has been laid in the trench, inspected by the TPIA/TGCPL, so as to provide a natural anchorage for the pipeline, thus avoiding long exposure of coating to high temperature, damaging actions of adverse weather conditions, sliding down of trench sides and pipe movement in the trench. If immediate filling is not possible, a covering of at least 200mm of earth, free of rock and hard lumps shall be placed over and around the pipe and coating. Before backfilling the trench, it shall be made sure that all the required work has been completed (CP, MDPE Pipe Laying, warning mat, mechanical protection etc.) as per specification. METHODOLOGY

25. The scope covers working methodology for the pre hydro testing of pipe sections of rail-road, road, minor water course, canal & mainline test headers and testing of HDD/Crossing String during the project execution Water filling and pressurization: All weld joints in test loop/section shall be radio graphically cleared and accepted before water filling. • Water Test Certificate of water used for filling shall be submitted to client Clean, not silty , with PH 6 to 8 and non-corrosive water shall be used for test. Water tank shall be deployed for filling operations in view of smaller length of strings. Pre Hydro Testing

26. Main and rear headers shall have provision for water filling, pressurization, venting, drainage and installation of pressure gauges. The strings shall be filled in full and ensured that there is no air entrapment. For all bolted fittings spiral wound gasket shall be used. Only calibrated pressure gauges and temperature gauges shall be used. Pressurization shall be done in the presence of the IOCL at a moderate and constant rate not exceeding 2 bar/min and pressurize up to the final test pressure as per IOCL Specification. Pressure shall be applied by means of a suitable test pump, which shall not be connected to a system until ready to test. In bringing the system up to the test pressure. An authorize operator shall attend to the pump constantly, during the test. The pressure shall be allowed to stabilize for a period of 15 min after attainment of test pressure during which pressure shall be established i.e. checked and test pump shall be disconnected the test section shall be completely isolated and all connections shall be checked for leakage. The test pressure ‘hold period ‘shall be 4 hours. Test section shall be visually examined for leaks/defects etc. Pressurize to test pressure 1.4 x Design pressures Pressure gauge of suitable pressure range (1.4 x pressures to be measured) and accuracy.

27. This procedure covers the work method for cleaning, water filling, thermal stabilization, hydro testing & dewatering of mainline works for the Steel Pipeline Construction Hydrostatic test shall be performed on the entire length of the pipeline. Hydrostatic test shall be performed in accordance with approved Hydrostatic Test diagrams for each test section. The maximum length of each test section shall not exceed 25 km. All buried steel pipelines shall be pressure tested after installation using water as a test medium minimum test pressure shall be equal to 1.4 times Maximum Allowable Operating Pressure. Final Hydro Testing

28. Equipment’s & Instruments :   The ES shall furnish all necessary equipment for performing the work as stated in cleaning, flushing, filling, leveling, stabilizing, testing and dewatering procedures. This shall include the following: Hydro testing cabin Pigs for filling, cleaning including Cleaning pigs shall be a Foam Pig of high & low density pigs. The ES shall provide sufficient number of pigs including spares . Fill Pumps : The ES shall determine the type and number of fill pumps in order to guarantee the following. Differential heads 20% greater than the maximum required. Flow rate min 40 m 3 per hour & max 60 m 3 per hour. Portable tanks during filling should be of sufficient size to provide continuous water supply to pressurizing pump. Variable speed positive displacement pumps equipped with a stroke counter to pressurize the line with a known stroke and capable of exceeding the maximum test pressure by at least 20 bar. Flow meter (2” turbine type) to measure the volume of water used for filling with calibration certificate. (Not older than six months) 1 thermocouple at about 500m distance from the pumping head and receiving head. 1 thermocouple at up to 2500m of the pipe the spacing depending on the terrain and nature of sub-soil along the alignment of section. 1 thermocouple at about 500m distance from the terminal head

29. This procedure defines the minimum technical requirements for the various activities to be performed by the ES for the engineering and construction of pipeline at major canal / river / Railway / State Highway / National Highway crossings using directional drilling technique List of Manpower Construction In charge Mechanical Engineers Stores Officer Safety officer Wire Line Engineer/Tracker HDD Rig Operator Mud Tank Operator Mechanic Electrician Riggers/Helper Unskilled Labors   HDD Crossing

30. List of Equipment : HDD Rig Mud Pumps Mud Mixing Machines Drill Rods Reamers Swivel Down hole Tools etc HDD Operations The drilling operation then begins by drilling a pilot hole using the drill bit, the drill head and the high-pressure injection of bentonite slurry. The drilling is carried out continuously in intervals of 10 feet (3 meters), equivalent to one length of drill pipe. A new length of drill pipe is added at the end of each interval . Once the drill bit exits end of the drill hole, the drill bit, steering tool etc are all detached and reamer is attached to the drill string.

31. The size of the back-reamed hole shall be 1.5 time of the pipe diameter for smooth pulling process The pipe string should be placed on the rubber lined rollers when direct carrier pipe is to be pulled. The rollers reduce the friction and hence decrease the pulling force requirement and the rubber lining prevents any damage to the coating. The pipe is then pulled back towards the Entrance area by the drill rig. The drill rig is then moved to the next drill site.

32. This procedure covers the work method for lowering-in of pipe section from ROW Welding position to trench bottom EQUIPMENTS Hydra 12 TON Capacity Excavator ex-200 Holiday detector (duly calibrated) Lifting belt / soft sling Dumpy level Coating repair crew Lowering of pipe

33. After satisfactory completion of trench bottom, the level shall be checked to get the required minimum cover. If the required further dressing of the trench shall be done to get the desired cover. Minimum cover shall be meeting specified requirement as per approved trenching method statement. Standard pipe cradle can be used and a demonstration shall be carried out that pipe coating is not damaged. Hydra/Cranes as required minimum numbers shall be used for holding the pipeline in gentle S curve maintaining the minimum elastic bending radius as specified in the job standard. The pipeline must be laid without interruption of whole section length available. Immediately after lowering level of pipe to be checked with level machine, same to be recorded for as –built. METHODOLOGY

34. The content of this Procedure covers the work method for pipeline pre commissioning for CHENNAI GA CGD Pipeline Project. METHODOLOGY: The interstation shall be carried out by purging Nitrogen continuously to the overall length of pipeline, proper venting shall carry out to ensure that all gases % contaminants inside the pipeline are vent out. The venting process shall be continued till the Oxygen % inside the entire pipe length comes below 2%. After obtaining required Oxygen level the vent shall be closed and purge Nitrogen to a pressure of 2 bar. Pre commissioning

35. A detail survey of the pipeline route before start – up of commissioning . Proper communication system to be checked & ensured proper back-up power supply for uninterrupted power supply for uninterrupted communication. Checking the electrical system & uninterrupted power supply during pipeline operation . Check all safety system & equipment properly installed & ready in working condition.

36. The pipeline will be commissioned in one section as detailed above from existing pipeline with Nitrogen & Natural Gas for the line sections, by blowing O2 and Natural Gas. The Natural Gas for the commissioning operations shall be supplied from starting Point (Zero point ). The commissioning basically consists of the following steps: O2 Freeing of the pipeline TOP. The O2 freeing of the pipeline will be done by Nitrogen propelled by Natural Gas after completion of Air Drying. Using the Natural Gas to bring the pipeline and stations under hydrocarbon atmosphere. Venting shall be carried out at the respective stations as and when found necessary. Commissioning

37. Indian oil corporation Limited GAIL(India) Limited Adani Total gas PVT Ltd Oil and Natural Gas Corporation Torrent gas Bharat Petroleum AG&P Partham city gas Some of CGD companies in India

38. Torrent Gas – 12inch & 8 inch pipe line Periyapalayam Thiruvallur to SIPCOT, Gummidipoondi . AG&P City Gas – 12 inch,8 inch & 6inch Location in Chennai GA IOACL – 8 inch pipe line in Cuddalore district IOCL – 12 inch pipeline in Salem GA IOCL -12 inch & 8 inch Madurai City to Virudhunagar . Upcoming pipe laying tenders in TamilNadu