1) Dry welding, also known as hyperbaric welding, is a process where welding is performed underwater inside a pressurized chamber filled with gas. 2) The first underwater welding was introduced by the British Admiralty in docks, and specialized underwater welding electrodes were later developed in the 1940s in Holland. Standard underwater welding procedures were established by the American Welding Society in the 1970s. 3) There are two main types of dry welding: cavity welding performed at one atmosphere, and habitat welding performed at hyperbaric pressure inside pressurized mini or large habitats on job sites. Automation and robots like THOR have improved the efficiency and safety of underwater welding.

1. GREATER NOIDA INSTITUTE OF TECHNOLOGY
SEMINAR ON UNDERWATER DRY WELDING
Presented To. Presented By.
Mr. ANUJ DIXIT MAHTAB ALAM
ROLL NO.1413240092

2. INTRODUCTION:-
Dry Welding/Hyperbaric
welding-
• Hyperbaric welding is
the process in which a
chamber.
• It is sealed around the
structuretube welding
and is filled with a gas
at the prevailing
pressure .

3. HISTORY:-
• First underwater welding introduced by British
Admiralty-Dockyard.
• In 1946,special waterproof electrodes were
developed in Holland by ‘Vander Willingen’
• In 1970s:First standard welding performed
Chicago bridge and welding procedure to
American Welding Society (AWS) standards.

4. Types of Dry Welding:-
1.Dry underwater welding at one
atmosphere(cavity method)
2.Dry underwater welding at hyperbaric
pressure(Habitat welding)
1.

5. Working

8. Type of habitat :-
• Mini-Habitat
• Large Habitat

9. Mini-Habitat

10. Large Habitat

11. New technology in hyperbaric welding
• The automation of the welding process
underwater has give a boost to the industry.
• “THOR(TIG hyperbaric orbital robot)”have
changed the way underwater welders do
things.
• Once they have reached the weld site, the
welders-divers must simply install the track
,orbital head and pipefit .afterward THOR take
over the rest of the weld.

12. Advantages of dry welding:-
• Welder/driver safety
• Good weld quality
• Surface Monitoring
• Non-Destructive Testing(NDT)

13. Disadvantages:-
• It requires large quantities of complex
equipment and much support equipment on
the surface.
• Cost of habitat welding is extremely high and
increases with depth.

14. APPLICATIONS:-
• Temporary repair work caused by ships collisions
or unexpected accidents.
• Offshore construction for tapping sea resources.
• Salvaging vessels sunk in the sea.
• Repair and maintenance of ship.
• Construction of large ships beyond the capacity
of existing docks.
• Repairs and maintenance of underwater
pipelines.

15. THANK YOU