Grünbauer BV
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Modern technology and large scale

We operate a rather unique high-capacity Haane-welding machine with twin welding torches, suitable for under-powder welding and CO2-welding. Heavy welds can be deposited in a single pass, so minimizing deformation. Welding lengths of over 30 metres are no problem for this plant. Whether it is a plate girder; or an omega-section girder; or a castellated beam; or a composite girder, made from split sections: we handle them at high speed while maintaining top quality.

The drawing of our Haane twin-head welding machine shows how we can handle very large constructions most efficiently. The welding arm can be swung 180°, to run either over the machine bed or over the low concrete floor in front of the machine. Here the free welding height is a spacious 2 metres. The horizontal range of the welding heads is 3,10 metres. The welding machine is laid out as a half-portal. This allows for (in principle) unlimited welding lengths. In the present situation, the machine bed is 30 metres long, but we have reserved sufficient space to increase this length to 50 metres should the need arise. Since the welding arm can be swung over from one side to the other, welding can take place alternately at both sides of the machine. While welding at one side, we do prepare the next job on the other side. One job finished? Swing over the welding arm and we can start on the next job immediately. In this way, the machine is fully 100% productive. Your advantage? Low welding costs!

Survey of the Haane machine. An immense plate girder is being welded.

A most impressive and enlightening example! This welded plate girder has flanges of 500 x 50 mm and a web of 1600 x 20 mm. The overall length is 14 metres; total weight 12 (metric) tons.

The machine deposits two flange welds at the same time, in a single pass. Then the girder is turned over and the opposite two welds are made, again in a single pass.

Usually, we weld under powder (the Union melt method). This is a most efficient welding method, particularly for long uninterrupted beads. Penetration is high, which is conducive to the strength and quality of the weld. Under-powder welding is also advantageous both in environmental and ergonomic aspects; the powder blanket protects the welders from sparks and splashes, and it prevents welders' eyes.

It is possible to deposit welds with a=7 mm in a single go. This reduces the overall heat-input in the work, which results in reduced heat distortion.

The Grünbauer welding machine is provided with an accurate computer-operated follower system, so that e.g. curved beams can be welded without a hitch. The machine positions the torches to within 0,1 mm. Another advantage of our machine is the high production speed. Using 3 mm wire, we deposit uninterrupted beads of a=7 mm in a single pass. Just compare this with the productivity of the minitrack-system, which uses wire of 1.2 or 1.6 mm! And of course, since Grünbauers Haane welding machine has twin welding heads, we deposit two welds at the same time. The feed speed of the welding arm is 0.5 m/min, so we produce 1 m/min of bead.

Detail of the welding heads. The machine is welding under powder. If required, we can change over to CO2-torches.

A comparison. When welding manually, in the case of uninterrupted beads, wire of up to 1 mm can be applied and the average welding speed will be 4 to 5 metres per hour (!) To get a=7 mm, one needs at least three passes. Therefore manual welding is prohibitively expensive. At the same time, the overall quality of the weld is less satisfying, as the heat input is much larger. Hence the weld distortion wil be greater.

The Haane welding machine is also very well suited for the production of omega-section girders, both those with flat tops and those with elongated side plates. We deposit one upper and the opposite bottom weld at the first pass; then we weld the remaining two beads in a second pass.

Grünbauers Haane welding machine is the only machine of this type and size in Holland. There are but 12 of these machines in the whole of Europe.

©  Johann Grünbauer  Tel (+31) (0)20 6990300  E-mail info@grunbauer.nl TOP