ما هوه اللحام تحت الماء؟؟؟

ما هوه اللحام تحت الماء؟؟؟
لة اي دح عنده معلومه عن موضوع اللحام تحت الماء وكيف يتم
ارجوا الافاده
به
كما ايضا يعرف بانه خطر كبير فما سر خطورته؟؟؟؟؟؟؟

CLASSIFICATION
Underwater welding can be classified as
1) Wet Welding
2) Dry Welding
In wet welding the welding is performed underwater, directly exposed to the wet environment. In dry welding, a dry chamber is created near the area to be welded and the welder does the job by staying inside the chamber.

WET WELDING
Wet Welding indicates that welding is performed underwater, directly exposed to the wet environment. A special electrode is used and welding is carried out manually just as one does in open air welding. The increased freedom of movement makes wet welding the most effective, efficient and economical method. Welding power supply is located on the surface with connection to the diver/welder via cables and hoses.
In wet welding MMA (manual metal arc welding) is used.
Power Supply used : DC
Polarity : -ve polarity
When DC is used with +ve polarity, electrolysis will take place and cause rapid deterioration of any metallic components in the electrode holder. For wet welding AC is not used on account of electrical safety and difficulty in maintaining an arc underwater.

هذا الملف تجد فيه الموضوع بالتفصيل
http://www.metalwebnews.com/howto/underwater-welding/underwater-welding.pdf

و عامة اللحام تحت الماء استخدامه قليل و يقتصر علي عمليات الاصلاح Repair و كذلك لحامات ال tie -in و العاملين في هذا المجال
في بلادناالعربية معظمهم أجانب لان اللحام تحت الماء يجب ان يجيد الغطس و بطبيعة الحال ان يكون لحام ماهر.