JCaprarulo,
If it is in the companies specs it will apply to all runs.
If you are welding a pipe in the 5G position from the bottom to the top you will start in the 6 o'clock position.
If you started in exactly the 6 o'clock position for each run you would have all your starts in the one place and subsequently all the stop/starts up the pipe would be in a similar position. This could possibly lead to a concentration of discontinuities (porosity/slag) in the weld area.When viewed on a radiograph this could look like excess porosity in the one area even though it is really only a small (possibly acceptable) amount of porosity in each subsequent run.If the stop/starts were staggered you could avoid the possibility of this problem.
Start your first run 1" off centre on the bottom of the pipe.
Start your second run 1" the other side of centre on the bottom of the pipe.
Third run can be started at centre on the bottom of pipe.
Continue starting in a different position all the way out and you will find that all your stop/starts are staggered.
This also applies to your stops, don't finish all your welds at exactly 12 o'clock.
Hope this helps,
Regards,
Shane