Weathering resistance

P.V.C. pipe when subjected to long term exposure to
ultraviotet (U.V.) radiation from suniight will suffer
surface damage. The following summary on effects of
U.V. radiation on P.V.C. pipe was extracted from the
Uni-Beil Handbook of P.V.C. pipe:

- U.V. degradation results in color change, slight
increase jin tensile strength, slight increase in the
modulus of tensile elasticity, and decrease in impact
strength in P.V.C. pipe.

UV. degradation does not conrinue when exposure to
U.V. radiation is terminated.

U.V. degradation occurs only in the plastic material
directly exposed to U.V. radiation and to an
extremely shallow penetration dapth (fraction of a

mitliemeter).

UeV. degradation of properly formulatad P.V.C. pipe
materfals normally occurs only after extended

exposure.

Manvitte, a major American P.V.C. pipe supplier, has
recommended yard storage life for P.V.C. pipe, without
the utilization of a protective covering, of {8 months
In the southern latitudes and up to 36 months in areas
such as the Lower Maintand. .

Abrasion

P.V.C. pipe provides good resistance to minor abrasion.
However, the structural strength of the pipe can be
reduced by deep scratches and gouges. By adhering to
the recommended handling, installation and inspection
procedures, damage to the pipa exterior can be
eliminated. .

CARCINOGENIC CONSIDERATIONS

Vinyl Chloride has bean idantified as a possible
carcinogenic agent. In view of this, concerns have been
raised about the possible migration of vinyl chloride from
the finished P.V.C. pipe to the potable water.

However, according to an American Food and Drug
Administration Circular, "in the case of polyvinyl chloride
potable water pipe, the Commissioner (of the Food and Drug
Administration) concludes that the data available at this
time Indicate that Vinyl Chloride may not reasonably be
axpected to be present in water drawn from a polyvinyl!
chioride water pipe system."

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