Pressure Piping and the ongoing issue of welding downhand vs. uphand.
Pressure Piping and the ongoing issue of welding downhand vs. uphand.
(OP)
I've run into the issue of downhand pipe welding (SMAW), using 7018, and the reasons why it's bad, and how some inspectors just don't care. I've usually chalked it up to the skill of the welder, and the circumstances of positions etc. Could someone please clarify for me if there are any code requirements to this anomaly? I've scoured SEC IX, B31.3 etc etc and I really couldn't find much. I know the difference between uphill/downhill and that the downhand thing is more or less a trade term, but I would really like to put this issue to bed. Thanks!





RE: Pressure Piping and the ongoing issue of welding downhand vs. uphand.
Production -> downhill, Speciality-> Uphill
Downhill Advantages
---------
Faster speed.
Smaller fillet legs.
Lower overall heat input due to faster speed.
Less distortion due to lower heat input.
Disadvantages
--------------
Harder to control arc track at faster speeds.
Possibility of greater number of slag inclusions.
Independent events are seldomly independent.
RE: Pressure Piping and the ongoing issue of welding downhand vs. uphand.
Independent events are seldomly independent.
RE: Pressure Piping and the ongoing issue of welding downhand vs. uphand.
Here you can find some ingredients to start a good discussion: thread794-187838: downhand vs uphill.
El que no puede andar, se sienta.
RE: Pressure Piping and the ongoing issue of welding downhand vs. uphand.
Because welding with E7018 with downward progression will no doubt be done with smaller diameter electrodes at lower current settings than when used in upward progression, deposition rates will be lower even though travel speed will be higher. If you want to weld downhill with low hydrogen electrodes, use E7048.
RE: Pressure Piping and the ongoing issue of welding downhand vs. uphand.