chase05
As far as links that pertain to this product, I have only found this thread:
http://www.masterplumbers.com/forums/forum_posts.asp?TID=6670
It appears that these failures are attributable to the dezincification of the brass fitting, the expansion rates of the different materials (pex pipe, brass fitting and stainless steel ring) and the ring not sealing entirely around the fitting.
Let me explain in more detail for each of the instances above as it is not the same issue that revolve around the Kitec fittings.
There are three reasons the RTI fittings are failing.
The first being dezincification. The zinc “leaches” out of the fitting in the form of a merangue once the water is introduced in the system (dezincification). This chloride-rich merangue then gets on the stainless steel ring and after a period of time eats through the ring. This process is called chloride induced stress corrosion cracking.
Coupled with the issue, each of the materials used in this system expand and contract at different rates once hot water flows through the connection. The pex piping and the brass fitting expand and contract much more than the stainless steel ring primarily because the stainles steel ring has a higher tensile strength. So what you have is the internal materials of the connection (pex pipe and brass fitting) trying to expand once heat is introduced and the stainless steel ring trying to “stay put”. Well with the chloride merangue eating at the ring and the expansion of the brass and pex pipe “pushing” on the ring, a failure occurs.
The last reason for the failure is that the stainless steel rings do not seal aroung the brass fitting entirely. The rings used leave a minute/microscopic “gap” where the head of the ring is sealed. That void in the seal allows for water to travel through the connection and after a period of time a “channel/grove” is created in the barbs of the brass fitting to the extent that it becomes a leak.
The above mentioned failures are entirely different from the Kitec/Zurn issues that are prevelant in the Las Vegas area, and I believe are going to occur each time cheap brass and stainless steel rings are used in making connections.
The only way to get around these failures is to get dezincified brass installed with a redeigned ring that is thicker and made of a different material (such as a Vangaurd copper ring) each time a connection is made.
Thanks.
