Valves are exposed to
corrosive environments both internally (media) and
externally (ambient conditions). Since either source of
attack can ruin a metal valve or a plastic valve, such as
PVC, each deserves serious attention.
Internal Corrosion:
Nil-Cor produces a variety
of material systems to successfully handle a wide range
of corrosive fluid applications. Selection of the right
material for each application is the key to success for
Nil-Cor, and we have the knowledge and experience to do
it extraordinarily well. Nil-Cor offers a variety of
composite systems tailored to the application at hand.
Nil-Cor composites are resistant to over 1000 commonly
encountered industrial chemicals and chemical combinations
To assist in selecting
Nil-Cor valve materials, Nil-Cor publishes a detailed
corrosion guide. Information in the guide is compiled
from several sources -
- Nil-Cor
Immersion Testing
- Resin Tests
by Dow (Derakane® Vinyl Ester)
and Phillips (Ryton® PPS)
- Nil-Cor
Application Database
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Corrosion
information is presented by concentration and allowable
maximum temperature. For immediate assistance, view our Quick Reference Corrosion Guide on-line. Other variables can
affect the suitability of a particular resin for a
particular service, such as the presence of solids or
extreme velocity. We recommend consulting with a Nil-Cor
factory sales engineer for application assistance before
making your final selection.
External Corrosion:
Hostile external
environments can destroy a valve just as surely as a
corrosive media. Metal valves often fail due to corrosion
of the stem at the packing box, resulting in freezing of
the valve. Other modes of failure include body, bolting
or handle rust-through. The following photos illustrate
the advantages of Nil-Cor's composite body and Hastelloy
packing gland, which are virtually invincible to
corrosive environments. (P.S.: We're so sure of this that
if any Nil-Cor valve ever fails from external corrosion,
we'll replace it free of charge, regardless of its age!)
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Metal Valves:
Destroyed by the environment |
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Nil-Cor
Valve:
Untouched by corrosion |
Ultra
Violet Exposure:
Nil-Cor thermoset and
thermoplastic composites are virtually unaffected by
exposure to sun light and UV radiation. This is in marked
contrast to PVC and other plastic valves that degrade and
fail after relatively short exposures. So for the long
term, Nil-Cor valves are frequently less expensive to own
and operate than plastic "throwaway" valves.
