Industrial Valves

5Material and Corrosion

5.1 Introduction

Valves are essential components of piping systems in the oil and gas industry. An oil and gas plant's efficiency, safety, and reliability largely depend on fluid handling and transportation through the piping system, including industrial valves. Material failure because of corrosion is known as one of the significant causes of valve failure. Some of the negative impacts of valve failure in the oil and gas industry, especially the offshore sector, can be summarized as loss of assets and production and Safety and Environmental issues (HSE), including problems like hydrocarbon (oil and gas) spillage and environmental pollution, loss of human life in some cases, jeopardizing safety and reliability, etc. Many valves fail every year due to poor material selection and corrosion. So, proper material selection and corrosion prevention are important aspects of the valve design.

Corrosion occurs when a material deteriorates due to its interaction with its surrounding environment. Corrosive oil and gas in upstream units such as wellhead and separation as well as downstream plants such as refineries contain a high number of undesirable corrosive byproducts such as carbon dioxide (CO₂) and hydrogen sulfide (H₂S). The most critical and complicated material calculation for industrial valves is corrosion allowance. It is important to know that corrosion allowance is selected to mitigate the corrosion produced by carbon dioxide (CO₂). Carbon dioxide is ...