|
|
|
|
|
|
|
|
| External Welding Machine |
|
The External Welding Machine is commonly called "bug". There are three basic
configurations: hot pass, fill pass and cap pass bugs which utilize the GMAW or pulsed
GMAW welding process. The bugs travel on steel bands that are attached to the pipe after
the new bevel has been cut and before the pipe joint is welded into the pipeline. The bugs
are supplied in left and right hand versions to allow simultaneous welding by two units on
one pipe band. Each bug makes half a weld pass from 12 to 6 o’clock, one in the
clockwise direction and the other in the counterclockwise direction. The latest versions of these bugs allow the same design to be used for both fill and cap passes with closed loop control over welding parameters. New developments will incorporate state-of-the art features such as microprocessor control, side wall tracking and parameter monitoring among other technological advances. |
|
