ABSTRACT
A general appreciation of the nature of corrosion is important in selecting pump materials, reviewing various designs, and correcting field problems. Corrosion is very broad subject, so the treatment following is cursory in the extreme. Materials used for pump construction fall into two categories: metallic and nonmetallic. Corrosion, by the narrower definition, is almost exclusively limited to metallic materials, whose electrons are free to move. While there are various special cases of metallic corrosion, all are fundamentally galvanic in nature. The essential ingredients are a potential difference between two sites immersed in an electrolyte and connected with an external electrical circuit. The types of corrosion covered so far are those clearly caused by electrochemical action. Nonmetallic materials used for chemical pump construction include rubber, plastic, ceramic, graphite, and glass. For practical purposes the last two materials are inert.
