Descripción: Pipeline pigging do's and don'ts and pigging selection guide
Full description
External pipeline coating
Descripción: Presentation of Unpiggiable Pipelines
Pipeline ManualDescripción completa
Pipeline ManualDescrição completa
Polyethylene Pipeline Code WSA 01—2004 Third Edition Version 3.1 Originated as WSA 01—1998 Previous edition WSA 01—2001Full description
Module : CGS / CPRS-DRS / Steel Pipeline
CGS •
CGS is the location of Custody Transfer from Transmission Company to Distribution Company
•
Basic Function of CGS is to
Filteration
Pressure Reduction
Custody Transfer metering
Odorization
Preheating of NG if required
CGS – Design Criteria •
Upstream Pressure
•
Downstream pressure requirement
•
Downstream flow requirements including peak flow rates
•
Future projections of volume growth / flow-rate
•
Future expansion
•
Consider safety at all stages
•
Reference Standards : IGE/TD/13
Major Elements of CGS • Suitable Land • Below facilities with a hot stand by mode : – – – –
Filtration (Knockout drum, Filter Cum Separator) Let Down Skid (PCV or PRV, SSV, CRV/SRV, Pressure Gauges) Metering (Turbine / Ultrasonic / Orifice) Odorization
• Pre-heating • Ball Valves • Station Piping & Supports • Electrical Work • Instrumentation work (SCADA / Control Panels)
Typical City Gate Station
Typical City Gate Station
Pipeline
•
Type of Pipelines: – Steel Pipeline • Transmission Pipeline (Up to CGS) • Distribution Pipeline (CGS Downstream, Ring) – Poly Ethylene Pipeline • Medium Pressure (4 Bar) • Low Pressure (110 mBar)
Requirement / Considerations for Steel Pipeline
•
Delivering Natural Gas at required pressure to : – CNG Stations – CPRS – DRS
•
Covering entire City / Town by forming a RING in the periphery of the city/town, to cater existing and forecasted demands
•
Consideration of future load of outskirts areas / developing areas
•
Future need of Looping / Interconnections
Steel Pipeline – Reference Standards Standard / Code
Title
PNGRB T4S
Technical Standards and Specifications including Safety Standards - CGD
ASME B 31.8
Gas Transportation and Distribution Piping Systems
ASME B 31.4
Pipeline Transportation Systems for Liquid Hydrocarbons and other Liquids
OISD-141
Design & Construction Requirements for Cross-Country Hydrocarbon Pipelines
OISD-214
Cross-Country LPG Pipelines
OISD-226
Natural Gas Transmission Pipelines and City Gas Distribution Networks
API 5L / ISO 3183
Specification for Line Pipe
API RP1102
Recommended practice for Rail and Highway crossings
API 1104
Standard for welding pipeline and related facilities
API 6D / ISO 14313
Pipeline Valves
DNV OS-F101
Submarine pipeline systems
Other References
Applicable Standards / Specs of ASME, API, NACE, MSS, BS and DIN
Stages of Steel Pipeline Project •
•
•
•
Conceptualization – Market surveys for deriving basic assumptions on demand – Study Alternatives – Initiation of Feasibility Study for Commercial / Technical viability Feasibility Report – Route Selection & Surveys – Hydraulics / Simulations – Estimation of Project Cost – Market Demand Assessment – Project Approval Engineering & Planning – Design & Sizing – Specifications & Tender Document preparation – Material Procurement / Release of Word Orders & Contracts – Acquire RoU / Permissions – Project Execution & Commissioning Operation & Maintenance
Route Selection / Surveys •
Considerations / Detailing Required – Pipeline Length – Type of Terrain – No of Crossings / Type of Crossings – No of Valves (Section/Tap off/Future Extension) – Obstructions / Limitations – Identification of Authorities for permissions
•
Type of Surveys – Topographical – Geo-Technical – Population Density Index (Location Class) – Soil Resistivity – Cadastral
Design / Hydraulics / Simulation •
Process – Simulation for Network Hydraulics is done in the SYNERGEE software – This is basically required to derive diameter of pipeline in such a way that required pressure at all locations can be achieved and future load projections can be ascertained – Formulae used for hydraulics : Colebrook White / Fundamental pipe equation with flow dependent friction factor – Roughness: Type of Material
Roughness (microns)
Steel – new pipe (= 10 Yrs old) With internal coating 10 – 15 Without internal coating 35 – 40 Steel – old pipe (> 10 Yrs old)
With internal coating 15 – 20 Without internal coating 40 – 45
Design / Hydraulics / Simulation
•
Process – Efficiency factor: 0.85 – 1, factor shall be determined by duly calibrating actual field data in the approved flow equation – Velocity: Max. allowable velocity of the gas in the steel pipeline section of CGD network shall be 30 m/s – STP: • Standard pressure : 1.01325 Bar (a) • Standard Temperature : 15.5 Deg C – Design Life: • Steel pipeline : 30 Years • PE Pipeline : 50 Years
Design / Hydraulics / Simulation •
•
Location Class: Class I
10 or fewer buildings in 1mile section
Class II
10 – 46 buildings
Class III
46 or more buildings
Class IV
areas where multistoried buildings and heavy underground utilities
Basic Design Factor: Location Class
F (design factor)
Class I
0.72
Class II
0.60
Class III
0.50
Class IV
0.40
Design / Hydraulics / Simulation
•
•
Location Class: Class I 10 or fewer buildings in 1mile section Class II 10 – 46 buildings Class III 46 or more buildings Class IV areas where multistoried buildings and heavy underground utilities Wall Thickness calculation for steel pipeline P = 2St FET D where P S D t F E T
Design pressure Specified minimum yield strength Nominal OD of pipe Nominal wall thickness Design factor Longitudinal joint factor Temperature de-rating factor
Line Pipes – Selection / Specifications •
Type – ERW – Seamless – LSAW – HSAW
•
Material Grade
•
Nominal Diameter and Wall Thickness
•
Length (single random / double random)
Coating Coal Tar Enamel Coating (BS 4164, AWWA C203) • Primer • Two layers of coal tar enamel & glass fiber Inner wrap • One layer of coal tar impregnated outer wrap • Coating thickness 4.7mm 3 Layer PE/ PP Coating (DIN 30670) • First layer of Fusion bonded epoxy • Second layer of extruded adhesive • Third layer of extruded PE/ PP • Coating thickness 2.0 to 3.7 mm Fusion Bonded Epoxy Coating (CSA Z245.20) • 350-500 micron thick single layer coating • 600-800 micron thick dual layer coating
• Scheduling of activities & milestones • Material Ordering / Delivery schedule
Mobilization
• Mobilization of Manpower & Equipment
Procedures / Qualifications
• Approval of procedures for various activities • Welding Preparedness (WPS/PQT, EQT, Welders Qualification) • Insulators’ qualification
Training
• Safety Trainings • Site Briefing
Readiness to Start Construction
• Kick off Meeting
Construction Stages •
Construction Activities
Activity
Description / Steps
Grading
• RoU clearance, Marking and cleaning
Trenching
• At Correct depth • With the help of Machines or Labors as per site requirement
Stringing
• With the help of Hydra or Side Boom
Welding & NDE
• Welding as per approved procedures by qualified welders • Non Destructive Testing – X-ray/UT/MPT/DPT
Joint Coating
• Heat Shrinkable sleeves or R-95 (Material TC required) • By qualified insulator
Lowering
• Lowering of pipe section • Tie-in Joints
Special Crossings
• River/ Drains/Railway/ Highways/ Canals • By HDD or Push Jack Boring
Backfilling & restoration
• Backfilling & Crowning • Manually / with Machine as per site requirement
Construction Stages •
Testing & Commissioning, Handover to O&M
Activity
Description / Steps
Cleaning
• Cleaning of pipeline prior to start hydrostatic testing
Hydrostatic Testing
• Water filling, Air volume calculation before pressure holding • Pressure Holding & Monitoring (min.24 hours after temp. stab.) • Dewatering & Cleaning
Valves
• Installation of Valves • Construction of Valve chambers
TCP
• Installation of TCP • Review readings
Readiness
• Readiness review of pipeline jointly by Projects/O&M team including review of documents/records/deviations, route visit, etc • Preparation of punch points, Compliance to HOTO procedure • Intimation to Local Authorities prior to Gas in.
Purging & Commissioning
• Purging with Nitrogen. Ensure <2% O2 before gas in • Commissioning
Hand over
• Handover to O&M for routine operations / maintenance
Project Management in GSPC Gas
•
Execution by Contractor
•
Inspection & Certification for quality by TPIA
•
Project Management by PMC
•
Overall monitoring by GSPC Gas
Photo : Steel pipeline site
CPRS/DRS : typical schematic
Photo : DRS/CPRS
Components
•
Filter : filter cartridge, DP Gauge
•
Two streams of : – Active regulator – Monitor regulator – Slam Shut off Valve – Creep Relief Valve
•
Pressure Gauges
•
Pilot regulators
•
Ball Valves
Design Parameters •
Maximum inlet pressure: 49 BarG
•
Differential Pressure (Min.) : 0.5 BarG
•
Outlet pressure range: 4 BarG
•
Flow rate @ min inlet pressure: 2000 SCMH/ 5000 SCMH
•
End Connections : 4”/6” depending upon capacity
Land Requirement •
30-36 Sq. Meter
•
No overhead electric lines / min. Distance 6 mtrs from HT/LT
•
Land should not be in a water logged area
•
Safe distance from Garbage collection/storage point
Installation & Commissioning •
Proper platform to be constructed
•
Inlet/outlet piping Installation as per the approved layout
•
Maintain proper alignment of installations
•
Proper support to inlet/outlet piping
•
Earthing to be provided
•
Vent height should be at least 3 meter from the ground level