2003 IMC

Robert O'Connor_12

Having not logged on to "Oil Tech Talk" in a while I can't seem to get on. Watsupwitdat? Anyhow, a tech posted this question:


jimtech
Dedicated Professional


Joined: 05 Aug 2005
Posts: 29
Location: Connecticut
Posted: Sat Jun 03, 2006 9:36 am Post subject: International mechanical Code

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section 1203.1.1 Joints between differant piping materials shall be made with appoved adapter fittings. Joints between differant metallic piping materials shall be made with appoved dielectric fittings or brass converter fittings.

Question: Is it O.K. to connect copper to black pipe without brass or dielectric fitting?

Question: Has anyone run into a problem with inspectors on this code?


Answer commentary:

Re: 03 IMC section 1203.1.1 Joints between different piping materials.

Numerous adapter fittings are available that are designed to join different pipe materials. When adapter fittings are used, they must be evaluated and shown to be compatible with the pipe material and working fluid. The fittings must also be rated for the maximum operating conditions of the hydronic system. When joining dissimilar metals, a method of protecting against galvanic corrosion is required. Galvanic corrosion occurs when two different metals are in contact in the preasence of an electrolyte, such as water. Galvanic corrosion accelerates the natural corrosion process that occurs in all metals and, because certain corrode faster than others, they have been placed in a hierarchy in order of rate of corrosion. The more reactive metal at a juncture is called the "anode" and the less reactive metal is called the "cathode". When metals of different reactivity are coupled, the more reactive metal (anode) will develope a surface layer of corrosion (such as rust on steel) or tend to dissolve in an electrolyte (such as water), thereby generating an electric current flow between the dissimilar metals. The rate of galvanic corrosion is strongly influenced by the difference in activity between dissimilar metals. The greater the difference in metals in the hierarchy of resistance to corrosion, the greater the reactivity between them and, therefore, the faster the anodic metal will corrode. The section, Jimtech referenced, prescribes two methods of protection against galvanic corrosion: dielectric fittings and brass converter fittings. These fittings are designed to provide a barrier or buffer between dissimilar metals in the waterway system or are designed to electrically isolate the metals from each other. Dielectric fittings include insulated couplings, insulated unions, and insulated nipples. Cast brass male and female threaded adapters are examples of converter fittings. This may or may not be the answer you were looking for given the fact that "most" residential applications simply use a copper x male adapters for transition between black and copper, so the "real" question is, "is this correct", and I would then have to say (with the code supporting it) no. If you are having difficulty, you may want to use an "approved" connection (transition) as been stated above to keep the inspector at bay.


Hope this helps!


Robert O'Connor/NJ


ps: could some kind soul please respond to this for me on the Oil tech board?? Or tell him I responded here.

Thanks!

Steamhead (in transit)

Done!

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Robert O'Connor_12

Thank You!

Robert O'Connor/NJ