Underwater welding can be classified as wet welding or dry welding. Wet welding is performed directly in water using manual arc welding, which has advantages of lower cost but risks of cracking and poor visibility. Dry welding uses a chamber near the work area and gas metal arc welding for better quality welds and welder safety, but requires more complex equipment and has higher costs. Underwater welding is used for ship repair and construction, offshore energy structures, and other underwater fabrication work, but poses electric shock and explosion risks that require inspections.

1. 
UNDERWATER WELDING

2. 
 S.C. MOI
GUIDED BY

3. 
 INTRODUCTION
 PRINCIPLE
 CLASSIFICATION
 WET WELDING
 DRY WELDING
 APPLICATION
 RISK INVOLVED
SLIDE PLAN

4. 
 WELDING: Welding is a process for joining two
similar or dissimilar metals
by fusion. It joins different
materials / alloys, with or
without the application of
pressure and with or without
the use of filler metal.
INTRODUCTION

5. 
 Underwater welding
is the type of welding
which takes place under
water. And this is an
important tool for
underwater fabrication
works.
UNDERWATER WELDING

6. 
 The work to be welded is connected to one side of an
electric circuit, via means of a cable. A flux-coated electrode
is attached to a holder, also connected via a cable, both being
attached to a power source.
 When the electrode makes contact with the work, an
electrical contact is made. The electric current jumps the gap
and created spark (arc), which melts the base metal and the
covering of the electrode forming a common weld puddle.
 Complete insulation of the cable and horses is essential in
case to prevent the chance for electric shock.
 Manual metal arc welding is commonly used in this
welding.
PRINCIPLE

7. 
 Underwater welding can be classified as:
1.WET WELDING 2.DRY WELDING
CLASSIFICATION

8. 
 WET WELDING:
* In the wet welding the welding is performed
underwater, directly exposed to the wet
environment.
* Supply is connected to the welder/driver via cable
hoses.
* MAW (Manual arc welding ) is commonly used in this
welding for repairing purpose

9. 
 ADVANTAGES:
* The versatility and low
cost.
* Less costlier then dry
welding.
* Tensile stress is high
* No west of time

10. 
 DISADVANTAGES:
* Decreases impact strength
and losses
* Poor visibility in water
* Chances of cracking
* Lack of experienced worker

11. 
 DRY WELDING:
• A chamber is created near the
area is to be the welded.
• A welder does the job by
staying inside the chamber.
• Gas metal arc welding is the
best process for this welding.

12. 
 ADVANTAGES:
* Welder/diver safety
* Good quality weld
* Surface monitoring
* Non destructive testing

13. 
 DISADVANTAGES:
* This welding require large quantities of complex
equipment
* Cost is extremely high
* For more depth more
energy is required
* Can not be weld if weld
spot is unreachable places

14. 
 Repairing and maintenance of ships
 Constructions of large ships
 Constructions for tapping sea
resources
 Temporary repair work
APPLICATION

15. 
 Electric shock Explosion
 Risk is to the life or health of
the welder
 Inspection of welds
 Hydrogen and Oxygen are produced during welding
RISK INVOLVED

16. 
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