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Type R 1090
Canada
14 Posts |
 Posted - 09/07/2003 : 13:09:39
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Any of you guys run across PEX water tubing in the course of your work?
Reason why I ask is I've recently been getting a number of liability claims for plumbers. All of them involve PEX water tubes coming off the compression fitting under the sink. I spoke to an engineer who wasn't aware of any problems, but mentioned that he heard that there may have been some litigation going on in the States with respect to it. |
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CCarr
Canada
1200 Posts |
Posted - 09/07/2003 : 16:05:55
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Hey T-R 1090, a fellow Beaver from the Western Pond in the lovely green valleys of socialist Lotus Land, where one can golf and ski on the same day - welcome to CADO whoever you are.
Pex tubing has been in approved use in America and in many other countries for about 25 years.
There are two standard application uses, first for radiant systems and the other for traditional potable (plumbing) systems.
There are known and reported failures of PEX tubing. The root of the failures seems to arise from pre-installation handling or storage, with the secondary cause of losses being improper installation. Ultraviolet rays have proven to degrade PEX tubing in under one month. In addition, there are allegations that if materials are mixed from different PEX manufacturers, it may void the product warranty.
Similar to the evolution of the "high / mid efficiency" furnace systems back in the early 90's and their usage of "High temperature PCV" tubing for direct venting, where that tubing failed many times due to improper installation techniques; at least one PEX manufacturer requires installers to complete a training course on the product or the warranty is void at the wholesale distribution point.
Other critics of PEX tubing point out that copper fittings are placed on the outside of copper tubing, while most PEX fittings are inserted into the PEX tube; resulting in restricted flow capacity in PEX product at the joint.
You specifically mentioned failures at the kitchen sink connection. Unlike copper which is non-porous and non-permeable, PEX tubing should not be exposed to cooking oils, certain insecticides and a number of pipe thread compounds and lubricants.
There are generally two types of installation of PEX over fittings. One type of PEX is meant to be stretched then allowed to contract over a fitting, but most types of PEX are meant to have the product clamped to a hose barb type fitting. This could easily be a "do-it-yourselfer" accident waiting to happen next month or year and hence potentially the claims you speak of. Apparently the least used connection system is the compression fitting.
I would suggest you let Google give you a pile of information to sift through regarding the product and it capabilities and limitations, and / or go to the astm.org or iapmo.org web sites for detailed information and installation standards.
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scottposton
USA
28 Posts |
Posted - 09/21/2003 : 23:49:35
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| I have spent the last 4 years doing Class Action claims for Polybutelene plumbing systems and as of yet have I ever seen a replumb made with pex using compression fittings. Your initial question states that these compression fittings are typically found underneath the sink. Have you examined other unions or fitting? Are they compression as well? Unless I am wrong and I think CCarr hit on this the use of compression fitting on this type of system isn't allowed by the mfg. Same reason PB claims under the class action aren't covered if they have compression fittings. They were specifically stated by the mfg originally as unsutitable fitting types. I have covered the east coast doing the PB claims and I see with original systems either brass/copper insert fittings or acetal insert fittings which were the only to allowable fittings by the mfg and the settlement. Rarely have I ever seen a plumbing system which was installed with compression fittings as part of the initial plumbing. Two reasons why? 1. Not cost effective and 2. Not recommended by mfg of PB....Again like CCarr alluded to in his post I think PEX requires an insert fitting to be used. |
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Type R 1090
Canada
14 Posts |
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PEX?
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