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Electrolysis 316 SS pipes on Galvanized pipe supports

I am installing a 316 Stainless Steel Pipe system carrying a gas mixture of appoximately 64% methane gas and some residual gasses from an anaerobic digester on a wastewater treatment plant. I am using hot dip galvanized carbon steel pipe supports in direct contact with the stainless pipe. Do I need to be concerned with electrolysis with regards to dis-similar metals? i.e. do I need to insulate the pipe support or use a stainless steel support?

Matthew ALLEN
Western Summit / Water Treatment Contractor - Denver, Colorado, USA
2004

It takes moisture and oxygen to get rust. The ss will rust from the contact with the galvanize, but how much and how soon will depend on the factors at that installation. Virtually anything that is a non conductor can be inserted between them and will greatly reduce the problems. This can be a fancy as a specialized clamp to just inserting slices of a milk bottle inside the clamp.

James Watts
- Navarre, Florida
2004

In some cases we use pad same as pipe material and .... if you like to get more information you can respond and I will explain more.

Kouresh Zanganeh
- Iran
2005

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Normally you should not connect two metal with different electrical potential since in the electrolyte area it starts with exchange of ions. This process is called 'Galvanic corrosion' and by connection of galv. carbon steel and stainless steel this type of corrosion will start at wet condition as stainless steel is an alloy combined of nickel-chromium and/or titanium which providing lower potential under zinc coated carbon steel.

In engineering practice we should avoid this phenomena by using elastomer pad like PTFE, NBR ,.... to isolate to different metals.

GHOLAMREZA HAGHIGHAT TALAB
- KL, Malaysia
2006