Hi Ed,
There is also some pitting in some of the 316SS pipe lines where pipes were not properly flushed before service (pitting in bottom 1/2 of pipe only).
As to gaskets, they are nitrile and they have seen degradation in that the are loosing their filler, so rubbing black on your hands. How...
Thanks for the information Edstainless.
The flow is quite high rate, not sure what the o2 content. Though I thought that crevice corrosion would be worse if it was high o2 content. WShat mechanism are you thinking for that reasoning?
Recent HX maintenance has shown extensive crevice corrosion...
Thanks gr2vessels.
My concern is that I have 2ppm of free chlorine, not just chlorides.
There does not seem to be any literature that sites the effect of the free chlorine on pitting.
There are references to it in chlorination of sea water for scum removal/control in offshore rig water...
Looking for information on corrosivity (crevice & pitting) on 316SS plate heat exchanger being used to heat RO permeate water.
The permeate has been hardened by addition of lime (about 30ppm hardness & 90ppm alk, pH 8), but has up to 2ppm free chlorine from hypo addition. Temp is 55-65 degC...
