Tank Girth Welder For Storage Tanks

Developing a girth welding machine for disinfection tank production is a tough task ahead for industries. Meeting the quality requirements is critical because tank girth welder control system requires the control of the core as PLC. It provides a variety of alternative welding mode and capacity of a large database of welding, so welding is adaptable, easy to operate.

With the large amount of welding required in the construction of storage tanks, contractors are resorting to automatic welding techniques to increase productivity and improve quality. To meet the stiff deadlines, a technical paper on automatic welding of storage tanks is required. The paper consists of all the position variable speed carriages using the MIG process. The acute shortage of skilled welders makes it more of a mandatory necessity to automate the welding process.

Equipment used for tank welding

The tank girth welder equipment used for storage tank fabrication falls mainly into four categories:

1. Electro-gas welder for vertical welding on shell butt welds

2. “3 O’clock” submerged arc girth welder for welding of circumferential seams

3. Programmable, all position welding carriages (used with the MIG welding process) for welding of vertical, variable speed and circumferential seams of tanks, floor plates, wind girders, floor plates to vertical shell welding, etc.

4. Auxiliary equipment, i.e., mechanical high speed bevellers, automatic gouging equipment, etc.

Electrogas welder: The electro-gas welder is an extension of the MIG process which is designed for carrying out vertical welds in a single pass. It can lead to high heat input and unrefined grain structure in special steels and ofcourse distortion.

3 O’clock girth storage: It can be a single or dual head type, where the dual head type has one head on one side of the circumferential seam and the other on the other side, so that the seam can be welded from both sides simultaneously. This equipment uses the submerged arc process at high speeds, and reduces the number of passes.

Welding carriage: The programmable, variable speed, all position carriages run on rigid or flexible tracks fitted with magnets can be mounted parallel to the vertical and circumferential seams of the weld. These carriages have controls for oscillation of the welding torch, programmed arc start, speed control, bead width and oscillation speed control, store and recall programmes, etc. A MIG welding torch is clamped onto the torch holding device, which can position the torch at any angle.

A highly skilled welder is not required for operation of the programmable, variable speed, all position carriage, as it welds automatically, oscillates the torch as it climbs up the track. It is fixed parallel to the vertical weld seam by means of magnets and vacuum cups on non ferrous weldments.

The main areas for tank girth welder of large storage tanks with programmable variable speed and position welding carriages are vertical welding of shell plates, welding of circumferential tiers of shells, tank floor welding butt/lap welding, shell to floor plate (inside and outside) fillet welding, dome to curb angle, wind girders, etc and roof welding.