A non conductive connection is required as Galvanic corrosion will occur that will locally corrode the steel pipe if it is in contact (electrically) with the more noble, SS pipe. In galvanic corrosion, a circuit is created due to the difference in voltage potential between dissimilar metals. Current flows through the electrolyte (water) and the metal to make a loop. The electron donor is the steel and thus also give up atoms which is corrosion
Gary W. Howard, P. Eng. Consulting Engineer [email protected] 416-843-1413 > On Feb 28, 2022, at 11:22 AM, Hinson, Ryan via Sprinklerforum > <[email protected]> wrote: > > Craig, > From literature I have, SS has an anodic index of approximately 0.60 V while > plain CS has that of 0.85 V. > > If the environment in which the joint is located is 'normal' or 'controlled', > you shouldn't have a galvanic compatibility issue. If the environment is > considered 'harsh', the anodic index delta must be smaller (approximately > 0.15 V) in which case, some sort of dielectric fitting/sacrificial anode > would be needed for joint longevity. > > As I am not an expert, I suggest reaching out to someone such as > www.corrosion-doctors.org for more assistance. > > Hope this helps, > > Ryan L. Hinson, PE*, SET** \ Burns & McDonnell > Senior Fire Protection Engineer > O 612-900-3755 \ M 763-688-4045 \ F 952-229-2923 > [email protected] \ burnsmcd.com > 8201 Norman Center Drive, Suite 500 \ Minneapolis-St. Paul, MN 55437 > *Registered in: AK, LA, MD, MN, PA, TX, & UT > **NICET IV - Water-Based Systems Layout > > > > -----Original Message----- > From: Sprinklerforum <[email protected]> On > Behalf Of Prahl, Craig/GVL via Sprinklerforum > Sent: Monday, February 28, 2022 10:06 AM > To: [email protected] > Cc: Prahl, Craig/GVL <[email protected]> > Subject: Joining black carbon steel with stainless steel piping > > I've got a engineer asking about the joining of grooved stainless to grooved > black carbon steel and if there needs to be a special dielectric or similar > type of assembly used to join the two? > > I've been hunting on the interwebs and haven't found any type of special > coupling or should the connection be flanged? > > In all my years this is the first time this subject has ever come up. > > Craig Prahl | Jacobs | Group Lead/SME - Fire Protection | > [email protected] | > https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.jacobs.com%2F&data=04%7C01%7Crhinson%40burnsmcd.com%7C2d6969ca91d4441ae22908d9fad44781%7Cbfbb9a2b6d994e78b3c795005d555c8b%7C0%7C0%7C637816612359587927%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=ln%2Ffq9qqoz%2FALwILLnsYh4I62399EES0Jp16yw6U%2FvU%3D&reserved=0 > 1041 East Butler Road Greenville, South Carolina 29606 > CONTACT BY: email or MS TEAMS > > > ________________________________ > > NOTICE - This communication may contain confidential and privileged > information that is for the sole use of the intended recipient. Any viewing, > copying or distribution of, or reliance on this message by unintended > recipients is strictly prohibited. If you have received this message in > error, please notify us immediately by replying to the message and deleting > it from your computer. > _______________________________________________ > Sprinklerforum mailing list > [email protected] > https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.firesprinkler.org%2Flistinfo.cgi%2Fsprinklerforum-firesprinkler.org&data=04%7C01%7Crhinson%40burnsmcd.com%7C2d6969ca91d4441ae22908d9fad44781%7Cbfbb9a2b6d994e78b3c795005d555c8b%7C0%7C0%7C637816612359587927%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=1HZ7rCOBMvIGnkxdF6EcTJYOIGN1cnyC8cQHktVKb4c%3D&reserved=0 > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
