Cover Production

Transformer cover is the top plate of transformer where input and output bushings, oil level indicator, thermometer, tap changer and lifting lugs are located. According to its Project cover plate is cut by plasma or laser cutting machine. Then its bushing studs, lifting lugs, thermometer pocket, oil filling cap, active part lifting part, non-magnetic LV bushing plate and conservator connection pipes are welded to cover the plate. Points that should be considered in the manufacture of the tank cover;

• Meeting the size and dimensions
• Meeting hole diameters and positions
• Avoiding of leakage from weldings,
• Avoiding welding burrs on surfaces,

NOTE: Applying edge bendings to cover plate increases endurance of cover. 

Frame Production

The component which connects tank body to cover plate is named as frame.

Frames can be produced from L angles or cut and bended steel sheet. A cover plate which is cut according to its project is used as a template to be able to drill frame holes. If it is requested in project Akabe produces additional NBR gasket frame from transmission sticks. Points to be considered in the manufacture of the frame;

• Meeting the size, angles and dimensions
• Meeting hole diameters and positions
• Avoiding of leakage at connections,
• Avoiding welding burrs on surfaces,

NOTE: Proper top surface of the frame will prevent oil leakage between the cover and the frame.

Fin Wall Production

Depending on customer request corrugated fin wall machine can produce a fin wall by using A1 quality DKP (CCR) 6112 cold rolled steel sheet material. Our corrugated fin wall paramaters are as follow; steel thickness is 1.2 or 1.5mm, width is 300~1600mm and fin height is 50~400mm. To strengthen the corrugated wall, welding machine is able to weld extra steel stick to both sides of the panel. Points to be considered in the manufacture of the corrugated fin walls;

• Meeting the size, angles and dimensions
• Avoiding aligning problems,
• Welding countinously to avoid leakage 
• Inner gaps of fin should not interfere with the movement of oil,

NOTE: Increasing the contact surface via corrugated wall will enhace the cooling effectiveness.

Bottom Plate and Footer

The bottom plate located on tank bottom which is cut by laser, banded by press brake and welded by MIG/MAG to bottom side of corrugated fin walls. It is protecting transformer tank againinist impacts coming from bottom side of tank. There is an oil draining valve on the side of bottom plate. Footer could be produced by MPU profile or steel sheet and welded to bottom plate.Points to be considered in the manufacture of the bottom plate and footer;

• Meeting the size, angles and dimensions,
• Meeting hole diameters and positions,
• Avoiding of leakage at connections,
• Avoiding welding burrs on surfaces,

NOTE: As an oil draning valve, MV22 valve or if it is requested ball valve also can be used according to design.

NOTE: Footer is produced according to its project, can be set up to bottom plate by spot welding, interrupted welding or continous welding.

Assmebling

Frame, short and long side corrugated walls and bottom plate which have been produced according to their projects are assembled and transformer tank is shaped in this step by spot welding. Templates are prepared before assemling eases this process. Points to be considered in the manufacture of the assembling:

• Meeting the width, length and height of tank,
• Meeting the angles,
• Suitable spot welding sizes,
• Avoiding leakages while spot welding,

NOTE: The assembling process is one of the most important phase of the transformer tank manufacturing and the faults that will occur during the assemling will cause a lot of trouble, from the defects in the structure of the transformer tank to the stress breakages that will occur in the final welding operations.

NOTE: After the assemling process, the transformer tank is sent to the final welding process by re-measuring.

Final Welding Process

The phase where the main welding operation of the assembled transformer tank is realized is called the final welding process. At this stage, welder welds edges of the junctions with the MIG/MAG welding. Points to be considered in the manufacture of final welding process;

• Good cleaning of welding surface,
• Using the right equipment,
• The technical staff should have adequate qualifications,
• Lack of inadequate melting and influence,
• Preventing crack formation,
• Avoiding foaming problems,
• Avoiding splashing problems while welding,

NOTE: In addition, If the material surface is not clean enough, the flow is high, the arc length is heigh, the welding metal is cooled fast, electrodes are wet, welding is fast, gas type is wrong, welding current and voltage is low, parts are welded in wrong order cause welding problems.