H 2S and SSC – A form of corrosion that is routinely encountered in oil and gas production applications is sulfide stress cracking, or SSC.…

Saudi Aramco Engineering Standard SAES-L-008 is titled Selection of Valves. Table I of this standard includes fluid and material compatibility guidelines. An excerpt from Table…

The Alloy Casting Institute (ACI) has developed a system for designating stainless and heat resistant casting alloys. As Figure 14 shows, casting designations begin with…

UNS designations have been jointly developed by the Society of Automotive Engineers (SAE) and the American Society for Testing and Materials (ASTM). This system provides…

General Properties Of Materials Following is a list of materials that are commonly specified for control valves: • Cast iron is a low cost, non-ductile…

Major Selection Considerations Previous sections have shown how the construction materials influence the pressure, pressure drop, and temperature ratings of a particular valve type. Material…

Pressure drop ratings are typically a function of the valve type, trim style, materials of construction, and fluid temperature. Manufacturers may publish maximum pressure drop…

In rotary-shaft valves, the surface area of the closure member is generally quite large as compared to the surface area of the bearings and bushings…

While the ANSI Class rating and bolting pressure limits describe the pressure retaining ability of a control valve, the internal components (trim) typically determine the…

Although the valve body and bonnet are the major pressure-containing components, other components such as the body-to-bonnet bolting can influence the pressure and temperature limits…