Corrosives 101


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

       

     


CORROSION GUIDE SUPPLIMENT FOR NEW AND
IMPROVED 500XP AND 610XP SERIES

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!)


Badly Corroded METAL Gate Valve
Corrosion Damaged FEP Lined Iron Plug Valve

Metal Valves: Destroyed by the environment

Nil-Cor Valve Untouched by Corrosion
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.

 


 

 
 
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