Innovative Tube Production Processes

Large diameter steel pipes – new proposal for on-site production

Big constructions often need very long large diameter steel pipes, having high wall thickness, maximum 3 m outside diameter, 50-60 m length and 30 mm thickness.
Typical applications are big buildings foundations and piling, dams and port constructions, peers and jetties
The transportation of such very long large diameter pipes is very expensive and sometimes impossible.

Vavit srl has developed a new concept design of a mobile pipe mill that can be easily dismantled and relocated on the job site in a few days, by the mill’s operators themselves, without special skilled technicians’ intervention.
The complete mill is a complex machinery having a total weight of about 400 tons.
The proposed mill is made of independent modules that can fit into 25 standard containers, each module having already on board all the electrical and hydraulic facilities needed for automation & control. The mill does not need special foundations and can be easily assemble on a regular concrete floor, just putting the modules in line and connecting the flanges.
The minimum production lot needed to justify the relocation of the mill is about 10-15.000 tons. This means that with about 5-6 weeks dedicated to dismantling, shipping and re-erection, the mill can re-start into a different site to work for a new project for minimum six–eight months.

Off-line tube squaring system – a reversible rolling concept Vavit srl has patented a new rolling concept to transform round tubes into square and rectangular tubes.

The round tube is gradually squeezed into the new shape with a reversible rolling, moving the tube back and forward between the forming rolls.
The reversible rolling is a very old concept, applied for rolling steel plates. Vavit srl has extended the idea in 2D – X-Y, moving the forming rolls up-down and right-left
to gradually squeeze and form the tube. The reversible rolling is processing one tube at a time, with a universal squaring stand that can be easily adapted for different dimensions.
The production can be done just in time, starting from a stock of mother tubes (round) that are transformed into square and rectangular shape on demand.
The complete process can be developed in a workshop of about 5000 sqm, with a capacity of 50-80.000 t/y.
The process is very interesting for medium-big carbon steel hollow sections, up to 500 x 500 mm.
It is less interesting for medium-small carbon steel hollow sections, where on-line forming is preferred.
It is interesting for medium-small hollow sections made in special steel, nickel alloys, titanium, copper, etc.
The typical application of big carbon steel hollow sections is for the construction of big buildings.

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