Welding while Pipe lifted by Crane

[ashfaqanwer]

Sometimes, in construction activities we come by with situations which are not looked very deep into and are ignored due to one priority or other.
During a site visit, it was observed that welding was in progress on a large dia piping while the pipe was being supported by Crane. See figures.
This activity has a serious concern pertaining to the root pass being welded as it can get cracked due to any small movement of Crane boom. And it is quite possible that the crack developed may not be picked up in radiography.

[1772]

Never seen it as a problem in my 35 yrs of welding and NDT atho I see your concern.

[ashfaqanwer]

For me it was also new but yes the concern is still there if I look this situation from an Inspection Engineer's eye.

[ben]

A new thing for me too...

[mechaengr]

Ashfaq...... standard procedure is that to join two pipes cleats are used which not only maintain the alignment but also maintain the root gap..... if pipe is suppoted with a mean that is not rigged then any movement is beared by theses cleats...and these donot permit relative movement.... So if standard procedure of cleat installtion is followed then i think no chance of such problem is there which you are talking about.......
Another thing which is specially looked into when welding some thing which is being holded by any crane.......if any mettalic sling or rope is used to rig the object then during welding current may flow into crane body through metallic sling or rope and crane boom...... this has directly effect upon electrical and control systems of crane, specially upon battery......... such incidents have happened in past...... so special care to be taken in this regard specially welding any eqipment holded on any fork lifter......and for cranes it is a good practice to use belts to lift objects upon which there is any requirement of welding while holding with crane....

[ashfaqanwer]

I appreciate your comments.
Thanks.

[mechaengr]

Your appreciation tells that you dont agree..........is it so....?

[ashfaqanwer]

No. You are right that if cleat would have been there, the risk stands negligible.
Unfortunately, I could not remember whether cleats were there or not.

[1772]

In this circumstance I have always used alignment clamps such as push-pull dogs or a Deerman clamp to maintain root opening and Hi-Low internal alignment.