316L S.Steel flow sensor on seawater filled Copper Nickel pipe

[markmanos]

Hi everyone,
I have a corrosion related question..
In our Yacht project, we have been supplied by our HVAC subcontractor with a set of:
ifm SI5000, flow sensors.
These sensors will be mounted on CuNiFer pipes and measure the sea water flow.
I am concerned about the fact that the sensor (316L) will be screwed in a CuNiFe nipple on the sea water pipe and the threads will be subject of galvanic corrosion (Stainless Steel + Copper Nickel + Sea water).
Can you please advise, would a electric isulation of the two threads will be enough?

Thanks

 

[EdStainless]

You do need full isolation, and don't expect the 316 to last too long even with good isolation.
The 316 will be susceptible to bio-fouling and corrosion.

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Plymouth Tube

 

[MechProjectEng]

If I remember correctly the SS316 may be cathodic with respect to the larger anodic area of the CuNiFer piping. I.e. The piping will try to protect the SS316 sensors?

However, also agree with Edstainless, best to avoid 316 for marine applications. We have had serious problems with pitting corrosion of SS316 on our project in the gulf. Warm water + high salinity.

 

[markmanos]

Thank's for the tips guys.