Gullco International of Ontario, Canada has for many years manufactured vertical overlay bridges / gantries mainly for the application of cladding boiler Tube sheets both in factory during manufacture and later for on site refurbishment.
These machines, whist being special are made largely from standard products from the world famous Kat travel carriage system.
These cladding machines have been developed to provide the many users with their distinctive requirements which include:-
- The ability to swing the vertical track to align it to the boiler tubes
- The vertical Kat can support and control two oscillator heads sometimes one metre away from the Kat
- Remote control of all 3 Kats
- Vertical Kat to sustain much more than its normal 45kgs capacity travelling vertical
- Be easily assembled on site, inside boilers
- Two welding heads working simultaneously
- In broken down parts the machine can be able to pass through a man way hole
- High speed vertical up return after vertical down weld
These boiler sheets are made from carbon steel, which if left without being clad would last only weeks in service.
The filler material used for this application is Inconel which is difficult to feed over distance, for this reason push-pull torches are normally used.
Once the vertical track is aligned to the boiler tubes the Kat will be started along with the welding machines and oscillators, the Kats will travel vertical down welding at 60cm/min until and end limit is reached.
The welding torches will be repositioned and the Kat will return at full speed to the top of the track to repeat the above.
These machines can be able to operate right from the boiler roof to the boiler floor. Welding can be carried out to the boiler floor.
The track configuration can also be reversed so that welding can be carried out to the roof.
Of course boilers have floors and roofs the equipment can be used for these too. The above photograph shows a machine in the overhead position.
In many factories where boiler tube sheets are manufactured the Vertical Kat track is also used as above but without horizontal tracks; in these case the vertical tracks are typically 6m long.