We have had an incident where a batch of pressure pipe (3600 meter) was delivered with welding defects. After examination by a third party laboratory the conclusion is “lack of fusion”. Enclosed is a picture of the typical defect.
The explanation from the manufacturer is that the reason for the damaged tubes is caused by voltage fluctuations of the incoming power to the factory. Incoming voltage is not logged, but as the manufacturer has found no deviations in other parameters controlling the production, they assume that the defects originate from voltage drops. The magnitude of the voltage fluctuations or how long they lasted is not known. It is not demonstrated by facts and figures that voltage fluctuations are the main cause of the defects in the tubes. This voltage fluctuation is also the reason that the eddy current testing was not showing any defects.
The statement from the owner of the group is that this can happen any time in the future and we have no guarantee that it will not happen again!!!
If this is correct any purchase of welded pipe from Italy must be a high risk activity.
I do not believe their explanation. Is there anybody out there having similar experience confirming this explanation from the manufacturer is correct?