Schmitt et al [9] have reported of similar corrosion failures of press fittings of 1.4401, flange joints and pitting at welds in German tap waters within short term exposure of < 2 years. In their study ennoblement was shown to occur for different surface qualities of 1.4401 in tap water and corrosion potentials up to 550-650 mV vs. SHE were measured. In a field test rig study with press fittings it was shown that chlorination lowered the corrosion potential and thereby reduced the risk of corrosion. For non-chlorinated water microbially influenced crevice corrosion could initiate in some water types, but not others, and it seems that the water treatment is of large importance for the tendency to ennoblement and for the subsequent development of crevice corrosion. It is especially interesting that a water quality with low degree of ennoblement can be changed by active charcoal filtration after which corrosion potential increases and redox potential decreases. Chlorination removes the effect and brings the corrosion potential back down and the redox potential up. Schmitt et al furthermore studied the effect of assembling aids for o-ring lubrication. In the case of chlorinated water there is no effect of the assembling aid, but in the non chlorinated water the electrochemical activity (corrosion) is higher, and the difference between the protectiveness of the aids become visible within a few months exposure. The authors furthermore suggest the use of 1.4435 with 2.5-3.0 mass % Mo to mitigate crevice corrosion. Ennoblement may also occur on this material, but corrosion will not initiate as easily as in 1.4401.