O-rings for Gas Sweetening Valves

Gas sweetening is a common unit process used in refineries, petrochemical plants, natural gas processing plants and other industries.

The glycol-based solvent chemistry together with Rapid Gas Decompression (RGD) environments can attack FKM valve seals and O-rings (typically located in the valve seat area) leading to shorter seal life, premature valve leaks and higher operating/maintenance costs.

One challenging application for Trunnion mounted ball valves is in gas cleaning/sweetening processes where acid gases such as hydrogen sulfide and carbon dioxide are separated from feed gas streams such as synthesis gas produced by gasification of coal, coke, or heavy hydrocarbon oils. Some of these gas sweetening processes operate under an acid gas removal glycol-based solvent.

DuPont™ Kalrez® 7090 perfluoroelastomer parts offer an excellent combination of chemical, RGD resistance, and high temperature resistance for O-ring applications in these types of valves handling glycol-based solvent.

Application

Ball valves are one the most common type of industrial valves used today. They use a rotating ball containing a hole that allows straight-through flow in the open position and shuts off flow passage when the ball is rotated 90 degrees. The valve is used for on/off and throttling services. These valves are used in a wide variety of industries including oil and gas, chemical processing, power generation and pump and paper among others.

Challenge

One challenging application for Trunnion mounted ball valves is in gas cleaning/sweetening processes where acid gases such as hydrogen sulfide and carbon dioxide are separated from feed gas streams such as synthesis gas produced by gasification of coal, coke, or heavy hydrocarbon oils. Some of these gas sweetening processes operate under an acid gas removal glycol-based solvent. Gas sweetening is a common unit process used in refineries, petrochemical plants, natural gas processing plants and other industries.

Solution

DuPont™ Kalrez® 7090 perfluoroelastomer parts offer an excellent combination of chemical, RGD resistance, and high temperature resistance for O-ring applications in these types of valves handling glycol-based solvent. The use of Kalrez® parts and components may extend the MTBR (Mean Time Between Repairs) of the valves and reduce leakage which can help contribute to reduced maintenance costs. The latest Kalrez® 0090 parts represent another option for this application when better RGD resistance and improved chemical resistance to water and hydrogen sulfide (H2S) is needed for temperatures that do not exceed 250 °C (482 °F).