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Underwater Cutting is used extensively in diving operations as they are mobile and are used in underwater construction, salvage and repair operations. This technique has enabled the marine offshore and inshore industries to save time and money due to its efficiency.
Cutting rods used underwater are designed to burn through almost any materials and at Dive-Marine Services Pte Ltd, we use the Broco's Cutting Rods which, burns at approximately 10,000 degrees at the tip of the rod.
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Underwater wet welding has become an accepted procedure for use in underwater construction, salvage and repair operations. This technique has enabled the fabrication of stronger welded joints. All divers had undergone training and received AWS D 3.6 Wet Welding Certification and DNV's certification and approval.
Electrodes used underwater are designed for straight polarity application and at Dive-Marine Services Pte Ltd, we use the Hydroweld Electrodes, Broco's Easytouch and Softouch Electrodes for better weld quality.
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External Welding Repairs - is performed usually on small to medium cracks/holes with the following procedures:
- Locate the ends of the crack/hole.
- Drill or burn small holes at the extreme ends of the crack to prevent further crack propagation.
- Prepare a plate of sufficient size to cover the cracked area and fit it into the contour
of the base material.
- Place the patch over the crack and attach by fillet welds around all edges. Continue welding until patch is watertight.
Internal Welding Repairs - is performed usually on larger cracks/holes with the welding performed internally if possible by inserting an insert on the inside and is performed with the following procedures:
- Locate the crack/hole.
- Install a 'cofferdam' on the external to prevent water from entering the damaged area. Internal cutting is performed according to size of the new insert plate.
- Installation of the insert plate and welding is performed internally.
- If necessary, underwater wet welding will be performed on the external upon the removal of the 'cofferdam'.
- Usually, such repairs are performed on exotic metals of the structures, aluminum, high tensile steel, etc.