PPR Fittings suppliers

Corrosion is the PPR Fittings suppliers and deterioration of materials under the action of various environments. The corrosion of metals is mainly caused by chemical corrosion and pitting chemical corrosion, and the corrosion of non-metallic materials is generally caused by direct chemical and physical damage. 1. The form of valve corrosion

There are two forms of metal valve corrosion, namely uniform corrosion and local corrosion. The rate of uniform corrosion can be evaluated by the average annual corrosion rate. Metal materials, graphite, glass, ceramics and concrete are divided into 4 grades according to the corrosion rate: the corrosion rate is less than 0.05mm/a is excellent; the corrosion rate is 0.05~0.5mm/a is good; the corrosion rate is 0.5~1.5 mm/a can still be used; corrosion rate greater than 1.5mm/a is not applicable

, valve sealing surface, valve stem, diaphragm, small spring and other valve parts generally use first-class materials, valve body, bonnet, etc. are suitable for two Grade or grade three materials, for valves with high pressure, highly toxic, flammable, explosive, and radioactive media, use materials with little corrosiveness. 1.

Uniform corrosion Uniform corrosion is carried out on the entire surface of the metal. Such as stainless steel, aluminum, titanium, etc., produce a protective film in an oxidizing environment, and the metal under the film will corrode uniformly. There is also a phenomenon, metal surface corrosion and peeling, this kind of corrosion is the most dangerous. 2. Localized Corrosion Localized corrosion occurs at the local location of the metal. Its forms include pitting corrosion, crevice corrosion, intergranular corrosion, delamination corrosion, stress corrosion, fatigue corrosion, selective corrosion, abrasion corrosion, cavitation corrosion, and friction corrosion. Vibration corrosion, hydrogen corrosion, etc. 

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