SEMINAR PPT

2. • Underwater welding is an important tool for underwater
fabrication works.
• In 1946, special waterproof electrodes were developed in
Holland by ‘Vander Willingen'’.
• In recent years the number of offshore structures including oil
drilling rigs, pipelines, platforms are being installed
significantly.
• Invented by Konstantin Khrenov in1930.

3. • Under water welding can be classified as :
1) Wet welding
2) Dry welding

4. 1. Wet welding
• Direct contact with water.
• Shielding gases.
• Quick water quench.
• All equipments insulated.
• Power supply by cables.
Fig. Wet welding process

5. Fig. Wet welding

6. 2. Dry welding
• sealed chamber filled with gases.
• Favorable condition for welder.
• High accuracy welding.
• A chamber is created near the area to be welded and the
welder does the job by staying inside the chamber.
• It produces high quality weld joints .
• The gas-tungsten arc welding process is used mostly for pipe
works
• Gas metal arc welding is the best process for this welding.
Fig. Mini-Habitat welding

7. • Tong Test Ammeter.
• Power converters.
• Safety knife Switches.
• Power Supply Requirements.
• All equipments is insulated.
Fig. Tong Test Ammeter

8. 1.Wet welding:
• Low cost.
• Enclosure not needed.
• Less time.
• No enclosures so no time is lost for
building
2.Dry welding :
• High accuracy welding.
• Unskilled welder.
• Driver safety.
• Non destructive testing
Fig. Wet welding

9. 1.Wet welding:
• Unstable platform.
• Poor visibility.
• Hydrogen embrittlement.
• Cleaning the surface.
2.Dry welding:
• Time consuming is more.
• Costlier.
• Complex process.
• Cost Is High.
Fig. Cleaning the
surface.

10. • Repairing of pipelines due to cyclones.
• Repairing of ships due to collisions.
• Oil drilling platform.
• Submarines use in war.
• Dams and bridges c
• New construction & installation structures.
• Subsea pipelines, & harbor facilities.
• maintenance and repair these includes repair of damage caused
by corrosion, fatigue
• Repairing holes in ship’s hulls or collision damage to harbor
facilities.
• Construction.

11. • Danger of an Electric Shock.
• Possibility of an Explosion.
• Decompression Sick.
• Hydrogen and oxygen bubbles are explosive.
• Danger of drowning due to failure of equipments.
• Danger of marine animals.

12. • Automation in THOR – 1 (TIG Hyperbaric Orbital Robot)
• A series of spot welds.
• Inspection done by ROV machine.
• Under water welding institutions.
fig. ROV machine

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