EXPERIENCE WITH Type 1 unplasticized polyvinyl chloride piping systems handling battery grade 93 percent sulfuric acid has shown this material to give excellent service if properly compounded and extruded. Polyvinyl chloride is potentially superior to lead or phenolic-lined steel since there is no possibility of metallic contamination.
The literature indicates that Type 1 unplasticized polyvinyl chloride is suitable for handling 93 percent sulfuric acid at ambient temperatures. However, failures have shown that much of the Type 1 PVC pipe is unsuitable for this service as manufactured today. An extension to a PVC line operating successfully for more than two years failed after seven months’ service. Failure occurred by permeation and embrittlement. Failed pipe exhibited profuse “sweating” while the external surfaces of the original section remained dry. Replacement sections obtained from a second and then a third manufacturer failed in like manner. The original section is still in service after more...
