Structural improvement of a control valve to prevent corrosion in acid gas treating plant pipeline: An experimental and computational analysis

A severe rupture of the carbon steel pipe next to a control butterfly valve caused a terrible explosion in real CO2 removal plant of a petrochemical company. Using data from on-site acid gas treating plant, the valve shortcomings was investigated via experimental analysis and computational fluid dynamics (CFD) methodology. Six various valve degree openings from theta = 5 degrees to 60 degrees was selected as the computational domains to clarify the link between localized corrosion thinning and the working fluid hydrodynamics. The high turbulence and rotational downstream flow can intensify the inhomogeneous deterioration of the surface in butterfly valve, due to its peculiar internal geometry. On this basis, an attempt was numerically made to improve the internal geometry of butterfly valve to avoid the high shear stress. Depending on the opening disk angle, the newly proposed model can reduce the wall shear stress by 20-90 times, that it is in favor of failure mitigation.