Flash Butt Welding

Patil Group of Industries is making its presence felt in the field of Flash Butt welding through its Flash Butt Welding plant at Moulali, Secunderabad, India.

Flash welding is a development of resistance butt welding and is particularly suitable for butt welding complex or larger sections. It is used for a wide range of component shaped and sizes from bicycle wheel rims to rails. More efficient energy input, and a more localized and evenly heated zone can be achieved, compared with resistance butt welding.

Welding of Rail Joints
Individual rails rolled in India are of 13 metre length. Rails, when laid in track can be joined either by provision of fish plates or by welding the rail joints. Welding of rails is done to convert the rails panels into long or continuous welded rail panels of a few kilometres length. These panels are called Long Welded Rails (LWRs) or Continuous Welded Rails (CWRs).

Welding of rails for conversion into LWRs/CWRs is another priority area in Track Modernization as this will facilitate smoother riding and also reduce the maintenance effort.

Flash Butt Welding
The individual rails of 13 m. length received from steel rolling plants are initially sent to Flash Butt Welding Plant at Moulali, Secunderabad. The individual rails are then welded into rail panels of 10-rail length by flash butt welding technique.

Flash butt welding technique involves pre-heating of rail ends by passing high ampere low voltage current and then the rail ends are cyclically brought closer and separated, which results in heavy sparking between the rail ends. After the rail ends are brought to a molten state, butting of rail ends is done under pressure.

Flash butt joints have very high fatigue strength and are preferred to other types of welds. The rail panels of 10-rail length and 20-rail length formed by flash butt welding are transported from the Flash Butt Welding Plant to the field locations by loading into specially designed railway flat wagons. These panels are unloaded at the site through specially designed end unloading chutes fitted to the rearmost wagon.