Crane Barge EB 503 Job during shutdown GTS-AA SPU Site.

OFFSHORE PIPELINE

OFFSHORE

1. Pipe Selection
    1.1.Seamless pipe used on 1" through 6" pipeline.
    1.2. ERW pipe used on 4" through 12" pipelines.
    1.3 DSWS pipe used on 16" and larger pipeline.
    1.4 Pipeline wall thickness  Design F = 0.72
    1.5 Riser pipe wall thickness Design F = 0.5

2.Offshore Design consideration
    2.1 Determine minimum bending radius of steel pipe in laying outline and ordering material
    2.2 Assure line will not float--> Weight coatings to increase specific gravity (normally 1.35), Anchors
    2.3 Pipe Grade-Hight Strengh pipe used to decrease thickness requirements for pressure required
    2.4 Consider crushing of empty pipe in deep water
    2.5 Consider bending and longitudinal stress on riser

3. Offshore Construction consideration
    3.1 Determine stressed in sag bend and overbend--> Stinger and tension floats
    3.2 Spud barge --> Shallow water 5 to 50 ft
    3.3 Laybarge --> Deepwater, 50 to 2200 ft ; 2" through 48" pipe
    3.4 Jack up barge --> 12 to 200 ft; 2" through 6- 5/8" OD pipe
    3.5 Pipe reel barge --> 12 to 1000 ft ; 2" through 12 3/4" OD pipe

4. Offshore burrying
   4.1 Plow --> Deep water and stiff clays, Plow can be used concurrent with laying of pipe
   4.2 Jet --> Used in waterdepth to 300 ft, handjetting by divers, machine jet after pipeline is laid
   4.3 Dredge --> Used in shallow water (marsh and bays)
   4.4 Pipeline cover --> 3 ft minimum up to 200 ft water depth
   4.5 Cover near platform --> 5 ft for 300 ft outward from riser
   
    

PROCESS AND PIPING DIAGRAM

Process and Piping Diagram

1. Process flow diagram

•     Often called mechanical flow diagram (MFD).

•     Describe the purpose of the facility
  
•     Prepared by the process engineer

     Contains : all major items of equipment, Flow path of the process fluid, Operating conditions at each step of the process, Material balance.

2. Equipment Arrangement Diagram

•     Often called "Plot Plan"
  
• Scaled plan view of the facility showing the location of : all major equipment, Buildings, walkways and escape routes, Prevailing winds (optional).
• Prepared by the facility design engineer
• Indicates the proper spacing of equipment which : minimizes fire and gas hazards, Aids in planning and piping layout, Aids in electrical area classification, Aids in hazards analysis reviews.

3. Piping and instrument Diagram (P&ID)

• Prepared by the facility design engineer
  
• Provides : Drafting with necessary data to preparethe construction drawings, complete design detail relative to equipment and piping
• includes the mechanical design of each item
• Shows the piping and instrumentation of the process in considerably more detail than plot plan or process flow diagram. Such as : Control sensors and actuators, Valves and piping specially items, Process pressure, temperature and flow levels, Equipment sizes, Line sizes and "spec breaks"

4. Piping and equipment isometric diagram

• Consists of a three dimensional, non perspective pictorial
  
• Shows pipe elevation