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International Journal of Modern Science and Technology, 1(1), 2016, Pages 12-16. 


Investigation on erosion-corrosion behavior of gate valve used in main water distribution line of Oman

Elansezhian Rasu, Salim Abdullah Khamis Al Senaidi
Caledonian College of Engineering, Department of Mechanical & Industrial Engineering,Seeb, Muscat.

Sulatnate of Oman.

Abstract
Corrosion occurs as a result of the interaction of a metal with its environment. The extent of corrosion depends on the type of metal. This paper focuses on the investigation on erosion- corrosion behavior of gate valve used in main water distribution line of Oman. The hydrant valves are critically eroded and corroded because of the poor quality of coatings. Hence different types of metallic coatings are proposed to eradicate the erosion corrosion problem on the valves. Samples were cut from the actual valves and different coatings such as nickel-phosphorus, zinc, chromium and epoxy coatings were coated on the samples. Different nano materials such as nano Al2O3, nano ZnO and nano CuO (40~50 nm size) were mixed with the coatings and corresponding coatings have been done. Electroless technique was used to coat Ni-P on the samples. Zinc and Chromium were coated by spray technique.  Epoxy coating was applied by brush. Different corrosion tests like atmospheric exposure test, wet corrosion test and erosion corrosion test were carried out on the different coated samples.  The qualities of different coatings were compared and results were analyzed. Coated samples were characterized with help of scanning electron microscope and optical microscope. The surface roughness of coated samples was measured using stylus probe surface roughness meter. The hardness of samples was measured using Rockwell hardness tester. Among the different types of coatings used the electroless Ni-P coatings with nano Al2O3 resulted in superior corrosion resistance with negligible corrosion formed after a period of 12 weeks exposure.

Keywords: Metallic corrosion; Coatings; Hydrant valves; Chromium; Electroless nickel coatings; Powder coating.


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ISSN 2456-0235

International Journal of Modern Science and Technology