Galvanized Pipe produced by hot dipping, which includes all of the galvanized sprinkler pipe commonly used today, has an alloy boundary layer between the carbon steel and the zinc chromate. Flaking or even complete removal of the zinc from the exterior or interior of the pipe does not completely expose the pipe to corrosion due to this boundary layer alloy as well as the galvanic properties of the zinc. In essence, it cannot be "peeled off" and is nothing like organic coatings such as paint or powder coating. Mark at Aero
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of rongreenman . Sent: Tuesday, April 08, 2014 8:36 AM To: [email protected] Subject: Re: galvanized piping I think (emphasis on think only) that Idod will last longer because of the manufacturing process. It's more a steel/zinc alloy than coated steel. That said I don't know for sure. Rust/corrosion does not occur in environments without oxygen, consider Lake Michigan where nothing lives below 100 feet and all those sunken ships have uncorrupted cargo waiting for salvage, so a nitrogen environment in place of an oxygen/nitrogen (air) environment (inside the pipe) should be devoid of any deterioration at all. On Tue, Apr 8, 2014 at 8:25 AM, Rod DiBona <[email protected]> wrote: > > A general question. Do you still believe that galvanized piping should > be used for most dry systems / dry standpipes? The makers of idod pipe > say yes. The makers of nitrogen generators say no. I had always > thought that it was better and that in GENERAL galvanized would last > longer. Over the last few years it seems like the tide has changed and > I have read studies that come to different conclusions. I understand > there are many variables but thank you for your thoughts. > > Rod at Rapid > _______________________________________________ > Sprinklerforum mailing list > [email protected] > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkl > er.org > -- Ron Greenman Instructor Fire Protection Engineering Technology Bates Technical College 1101 So. Yakima Ave. Tacoma, WA 98405 [email protected] http://www.bates.ctc.edu/fireprotection/ 253.680.7346 253.576.9700 (cell) Member: ASEE, SFPE, ASCET, NFPA, AFSA, NFSA, AFAA, NIBS, WSAFM, WFC, WFSC They are happy men whose natures sort with their vocations. -Francis Bacon, essayist, philosopher, and statesman (1561-1626) A problem well stated is a problem half solved. -Charles F. Kettering, inventor and engineer (1876-1958) _______________________________________________ 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
