A solution for an application I am dealing with requires 316LSS and a 99.7 to 99.9% pure Aluminum alloy coexist in an ultrapure de-ionized H2O (5-20microS/cm^2) reservoir.  
There has been some debate among my colleagues and I as to whether galvanic action will occur in pure water, and whether I am making enough of a battery to break down the passive, and or oxide layers and cause corrosion.  
About 1/4 of the water circulating through the reservoir will have been entrained in an H2 gas stream and may contain a small amount of dissolved H2 but will be passed through a ion exchange resin bed before the reservoir.
The SS is a fitting threaded into the Al which goes to a SS solenoid valve.
Downstream contamination over lifetime are huge concerns so I'm looking for a head start on the testing.


I cross-posted this to corrosion engineering.  If this is discouraged I'd like to hear about it.
Thanks