Oil & Gas Pipeline Design, Maintenance & Repairs Prof. Dr. Abdel-Alim Hashem Min., Petr., & Metal. Eng. Dept. Faculty of Eng.- Cairo University Giza 12613 - Egypt
WARNING GAS PIPELINE BEFORE EXCAVATING OR IN EMERGENCY
CALL YOUR LOCAL CITY NATURAL GAS SYSTEM • DAY OR NIGHT (000) 000-7777
Course Objectives • The main objective of this pipeline course for engineering students is to familiarize them with worldwide engineering education techniques and systems in the field. • Pipeline, specially gas has a lot of benefits as well as a serious hazards for people and environment. Engineers as well as community need to be aware of these benefits and hazards. • This course is structured to give the student the basics of pipeline design, maintenance and repairs to offer benefits and avoid hazards for community and environment.
Contents • Class location and their recommendations • Pipeline Design • • • •
Materials of Construction Steps and Calculation Procedures Corrosion and cathodic protection Fittings, valves and accessories Installation
• Pipeline Maintenance and Repairs • • • •
Pigging Operation and Inspection Pipeline defects Pipeline rehabilitation Pipeline repairs
• Pipeline data and operations Forms • Pipeline Cost Analysis • Case Studies, Pipeline Network and design
Text Books & References • Antaki, George A.: Piping and pipeline Engineering: Design, Construction, and Repair (Mechanical Engineering, Volume 259) Amazon.com, $135, walmart.com, $ 121.5. • Pipeline Roles of Thumb Handbook, Fifth Edition, by W. McAllister, Amazon.com, $95 • Course notes will be handed to the students
Other References • Lee, R.R.: Pocket Guide to Flanges, Fittings and Piping Data, By Amazon.com, $36.9 • Frankland, Thomas W.: The Pipe Fitter’s and Pipe Welder’s Handbook, Amazon.com, $16.98 • Graves, W.V.: The Pipe Fitters Blue Handbook, Amazon.com, $16 • Peabody, A.W.: Control of Pipeline Corrosion, Amazon.com, $67 • ASTM and ANSI Standards
• Home Work and Projects • Problem Sets are attached • Sample Exams are Attached • Projects will be assigned Later
• Credit Hours (3) [30 Lectures & Tutorial] • Grading System: • Attendance (5%) • Assignments (5%) • Midterm exam (10%) • Case study (5%) • Presentation (5%) • Final exam (70%) --------------------------------------------• Total (100%)
List of Lectures Lectures Topics 1
Introduction and Location Class
2
Pipeline system Pipeline materials Steel pipe, Plastic pipe, Copper pipe Marking materials Transporting pipe Qualification table
Class location • A "class location unit" is an onshore area that extends 220 yards (200 meters) on either side of the centerline of any continuous 1-mile (1.6 kilometers) length of pipeline • Class 1: An offshore area; or any class location unit that has 10 or fewer buildings intended for human occupancy. • Class 2: Any class location unit that has more than 10 but fewer than 46 buildings intended for human occupancy.
Class location (Cont.) • Class 3: Any class location unit that has 46 or more buildings intended for human occupancy; or an area where the pipeline lies within 100 yards (91 meters) of either a building or a small, welldefined outside area (such as a playground, recreation area, outdoor theater, or other place of public assembly) that is occupied by 20 or more persons on at least 5 days a week for 10 weeks in any 12-month period. • Class 4: any class location unit where buildings with four or more stories aboveground are prevalent
Location class recommendations Class 1
No. of Buildings 11-25
Maximum Allowable Operating Pres (MAOP) MAOP or < 0.73 SMYS
2
26-45
0.8 Test P. or < 0.73 SMYS
2
46-65
0.667 Test P. < 0.6 SMYS
3
> 65
0.667 Test P. < 0.6 SMYS
4
Multi Story
0.555 Test P..< 0.5 SMYS
Length of class location • Length of Class locations 2, 3, and 4 may be adjusted as follows: – Class 4 location ends 220 yards (200 meters) from the nearest building with four or more stories aboveground. – When a cluster of buildings intended for human occupancy requires a Class 2 or 3 location, the class location ends 220 yards (200 meters) from the nearest building in the cluster.
Petroleum gas systems • Each plant that supplies petroleum gas by pipeline to a natural gas distribution system must meet the requirements • Each pipeline system subject to this part that transports only petroleum gas or petroleum gas/air mixtures must meet the requirements of ANSI/NFPA 58 and 59
F ig u r e I-1
P ro d u c in g W e lls
N a tu ra l G a s P ip e lin e S y s te m G a th e rin g L in e s
T ra n s m is s io n L in e
P ro c e s s in g P la n t
C o m p re sso r S ta tio n s L N G
P la n t
C ity G a te
U n d e rg ro u n d S to ra g e
L a r g e V o lu m e C u s to m e r
D IS T R IB U T IO N S Y S T E M
M e te r
R e g u la to r
Materials • Able to maintain the structural integrity of the pipeline under temperature and other environmental conditions that may be anticipated; • Chemically compatible with any gas that they transport and with any other material in the pipeline with which they are in contact • Qualified in accordance with the applicable requirements
Steel pipe • Carbon steel • Alloy steel
Steel pipe • New steel pipe is qualified for use if: – Manufactured in accordance with a listed specification; – Meets the requirements of the design – New steel pipe that has been cold expanded must comply with the mandatory provisions of API Specification 5L. • Used steel pipe is qualified for use if: • Manufactured in accordance with a listed specification and it meets the requirements of • Meets the requirements of design • Has been used in an existing line of the same or higher pressure and meets the requirements of design
Steel pipe • New or used steel pipe may be used at a pressure resulting in a hoop stress of less than 6,000 psi (41 MPa) where no close coiling or close bending is to be done (good condition and free of split seams and other defects that would cause leakage) • To be welded, steel pipe that has not been manufactured to a listed specification must also pass the weldability tests • Steel pipe that has not been previously used may be used as replacement pipe in a segment of pipeline if it has been manufactured prior to November 12, 1970, in accordance with the same specification as the pipe used in constructing that segment of pipeline.
Plastic pipe • New plastic pipe is qualified for use under this part if: – Manufactured in accordance with a listed specification; – Resistant to chemicals with which contact may be anticipated. • Used plastic pipe is qualified for use under this part if: – Manufactured in accordance with a listed specification; – Resistant to chemicals with which contract may be anticipated;
Plastic pipe (Cont.) – Used only in natural gas service. – Dimensions are still within the tolerances of the specification to which it was manufactured; and, – Free of visible defects. • Pipe of a diameter between the sizes included in a listed specification may be used if it: – Meets the strength and design criteria required of pipe included in that listed specification; and – Manufactured from plastic compounds which meet the criteria for material required of pipe included in that listed specification.
Marking of materials • Each valve, fitting, length of pipe, and other component must be marked: • As prescribed in the specification or standard to which it was manufactured, except that thermoplastic fittings must be marked in accordance with ASTM D 2513; or • To indicate size, material, manufacturer, pressure rating, and temperature rating, and as appropriate, type, grade, and model. • Surfaces of pipe and components that are subject to stress from internal pressure may not be field die stamped. • If any item is marked by die stamping, the die must have blunt or rounded edges that will minimize stress concentrations.
Transportation of pipe • In a pipeline to be operated at a hoop stress of 20 percent or more of SMYS, an operator may not use pipe having an outer diameter to wall thickness ratio of 70 to 1, or more, that is transported by railroad unless: – The transportation is performed in accordance with API RP 5L1. – In the case of pipe transported before November 12, 1970, the pipe is tested to at least 1.25 times the maximum allowable operating pressure if it is to be installed in a class 1 location and to at least 1.5 times the maximum allowable operating pressure if it is to be installed in a class 2, 3, or 4 location. The test pressure must be maintained for at least 8 hrs.
Reuse of pipe • Reuse of steel pipe • Remove a part of steel pipe and reuse it any where at the same or lower pressure is permitted except in offshore application • Used steel pipe and unidentified new steel pipe may be used for low stress (< 6000 psi hoop stress) no close coiling or close bending • For use at hoop stress above 6000 psi table of qualification have to be checked
Used pipe qualification table Process Inspection
unknown Specs. A
known specs. A
Bending, coiling
B
…
Thickness Joint longitudinal Weldability Defects Yield strength S Valve Test S Valve
C D C F G H I H
C D ….. F … ….. i …..
Qualification table Process Inspection Bending,.. Thickness Joint factor Weldability
Description Pipe cleaned inside & outside
Cold bent through 90 deg. or flatten test measuring at quarter points not < 10% See design table Qualified welder shall make a girth in the pipe, weld tested with API 1104 Surface defects Examined for gouges, grooves and dents Yield strength Test at 24,000 psi S value Min. value of Y St or 80% or Ave Hydrostatic Establish max. allowable pressure
Reuse of plastic pipe • Reuse is permitted if • Meets the requirements of ASTM D 2513 for new thermoplastic pipes • Free from visible defects • Installed and tested according to the new pipe
