There are many difficult applications for valves. High temperatures, abrasive solids, corrosive fluids, and rapid cycling are just some of the conditions which challenge the industry. Both isolation and control valves must designed appropriately. The valve industry has referred to these applications as “Severe Service. ”The problem is that there is no precision relative to the definition. The annual market for these valves is anywhere from $6 to $14 billion/yr depending upon how you define SSV. As a result we are working with the industry to obtain consensus . . We were delighted to learn that Ross Waters president of CGIS has been active in defining severe service valves. His company has extensive and lengthy experience in the supply of severe service valves in multiple industries in various countries. We interviewed him on the subject and obtained some insightful answers. We then chose one application: molecular sieve switching valves to serve as an example Historically the rising stem ball valve ( RSBV) has been used in this application. But the selection is complicated and depends to some extent on the severe conditions. Flowserve generalizes that this valve with its friction-free linear movement and mechanically energized metal seat. Has proven it to be the most suitable design for optimal long-term performance in severe applications, Cameron also recommends the rising stem ball valve. Cameron says it provides tight shutoff, withstands frequent cycling, and handles high temperatures better than other valve types in this service. ValvTecnologies draws some different conclusions based on specific experiences. They say that more long-term success has been realized with metal seated quarter turn ball valves and can cite installations were the rising stem ball valves have been replaced. ValvTechnologies’ zero-leakage carbide coated metal seated ball valves were selected and installed for a major operator’s sour gas plant in Monkman, British Columbia, replacing rising stem ball valves that lasted one year in service. These valves feature the same design proven since ValvTechnologies’ produced the seat supported fixed ball design. The first installation in a molecular sieve lasted eight years after its initial installation, providing severe service zero-leakage isolation. Given a conservative one day shut-down per year to replace other designed valves in a plant processing 220mmcfd of saleable gas at $750,000 per day, that is $6.0Min improved efficiency over the course of eight years.

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• Cameron International

• CGIS

• Flowserve

• Valvtechnologies

• High Performance Valve

• Molecular Sieve

• Valve

• 4/11/2016

• Article