PB Problems

Fitting
The primary concern with PB plumbing has been the fittings, which connect the 10-foot or shorter sections of pipe.  The original acetal resin-based fittings are suspected of deteriorating when exposed to chlorinated water.   In addition, crimp rings, which apply pressure to the PB pipe seal the PB to the fitting, made this section of the system more susceptible to failure when the plastics deteriorated.  The industry first blamed all problems on faulty installation, but lately has acknowledged that the plastic fittings have been a major problem. The original barbed insert fittings made with an acetal resin and the type of fitting and crimp rings used have undergone numerous changes.  The original aluminum crimp rings were changed to copper; the crimping tool was redesigned several times; and the acetal fittings were replaced with the copper and brass fittings that are still in use today.

Piping
Though the primary focus of the debate has revolved around the fittings, PB pipes have also undergone modification to produce a stronger, more durable product.  Premature deterioration and failure of the pipe has occurred.  

There are many theories on the cause of the premature deterioration and failure of the pipe. One theory is that when the piping is stored outdoors for a period of time or exposed to sunlight after installation, ultraviolet (UV) radiation from sunlight adversely alters the chemistry of the plastic, causing deterioration. The second theory for the premature deterioration and failure of the pipe is a reaction to oxidants (e.g. chlorine) in the drinking water.  However, no studies or information can support those theories at this time.  The manufacturers, even today, continue to maintain that the failures with the PB tubing are due to installation errors and/or misuse rather than product failure.

Heating Systems
A secondary concern involves the use of PB pipe for hot water heating systems.  The pipe allowed the oxygen to penetrate the pipe and oxygenate the water.  The additional oxygen in the re-circulated water was suspected of causing the premature rusting and deterioration of the internal components of the heating unit, including the boiler, heat exchanger and water pump.  The PB pipe has since been modified with a coat to prevent oxygen from penetrating the pipe walls.

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