Valves Material Specifications

Valve design and selection of materials are key factors when determining the different oil and gas media applications of valves. The two main things that affect the valve material selection are the strength of the valve and the corrosive media going through the valve.

Strength in a valve is its ability to withstand the internal stresses generated by containing and controlling the fluid under pressure. Strength can be measured in several ways, but the most common measure is by quantifying the metal’s tensile strength. Higher pressures are reserved for the stronger steel and high alloy valves as lower pressures can use lower tensile strengths such as cast iron.

The second major consideration in choosing a valve material is its corrosion resistance. Corrosion is the breakdown of a metal due to attack by various chemical reactions. The dangers of corrosion damage are particularly high in the chemical manufacturing industry where the issues of strong chemicals, high pressures and high temperatures cross paths. The harsh acids and other compounds can sometimes eat through metals such as iron and steel in a matter of days or even hours.  In valve materials, basic exterior rusting of the valve is usually secondary to the corrosion going on within the valve due to the unique characteristics of the fluid contained inside it.  In addition to the fluid going through the valve, the temperature of the flow media and the operating environment are other key factors to be considered when determining materials as it relates to corrosion.