Electrolytical pickling tunnel for stainless steel tubes

Present and future of stainless steel pickling is increasingly called "Electrolytic". Since the first industrial plant in line for stainless steel pipes installed at Marcegaglia Forlì in the year 2000 up till now, a lot has been done and the implementations at customers have been different; these have allowed Condoroil to achieve excellent optimization in the tunnel operation with complete satisfaction of customers.

The use of this system has meant that the processing times on particularly hostile alloys such as duplex and superduplex dropped below two minutes compared to the previous 30 hours (by immersion). An induction annealed welded tube in AISI 316L is pickled in 15 seconds!

This reduction in time mainly derives from the high work potential that goes from 300-800 mV of a chemical bath to over 10 V of the electrolytic process, allowing to work well above the area of passivity. In-line treatment of pickling also means substantially reducing what is the second cost for the pipe industry after the one related to the material: logistics.

Today, in the industries that have chosen to work with Condoroil's electrolytic unit, the tubes leave the line ready to be shipped to the customer, without the need to move the bundles all over the workshop avoiding, besides a substantial losses of time, even a substantial increase in risks. Speed means saving and saving means the possibility of being competitive on the market, a necessary condition to achieve the necessary levels of turnover for all types of industries in the welded pipe sector.

As economic advantages we should also add the striking difference in cost between a sulfuric based electrolytic solution and an hydrofluoric solution that can be calculated around the twentieth part. If we add to the great economic advantages other equally important ones concerning safety (for electrolytic pickling you do not use hydrofluoric acid), ease of processing emissions (no nitrous oxide or hydrofluoric acid fumes), possibility to work in closed loop, we realize that there are no reasons not to switch to the in line electrolytic pickling.

Today in Italy Condoroil has installed 15 working lines. Plans for future implementations in Europe are numerous and this, combined with the full satisfaction of customers, gives Condoroil the enthusiasm and energy to continue in this direction with the certainty to contribute "tunnel after tunnel" to enrich the stainless steel tube industry with increasingly productive and fewer toxic equipment.