Control and reduce fugitive emissions with control valves     The prevention and further reduction of fugitive emissions of volatile organic compounds (VOC) is one of the most important issues in the industrial world. Fugitive emissions need to be reduced due to their detrimental effects on health and the environment. This article describes potential technical options and solutions for control valves currently available and provides a forecast on future solutions....
	Control Valve Performance Issues     Control valves can have a major impact on control loop performance, which means improvements in valve performance can lead to significant operating benefits, say James Beall and Clinton Anderson from Emerson Process Management. In this article they show how poor control valve performance can be identified and corrected. A plant exampìe is used to demonstrate these methods. ...
	Flowserve is the Max (Safety first and foremost)   In this interview with Valve World, Flowserve's Mr Marc Van den Bosch discuuses the concept of SIL, or Safety Integrity Level(s)....
	Control valve actuators: their impact on control and variability A control valve actuator is used to move the valve stem (which is attached to the internal control element) to the desired position and hold it in place. In addition to the act of moving and holding positions, there are many other parameters to that movement which determine the best type of actuator that should be used for every specific application. In this paper, Chris Warnett looks at the impact control valve actuators can have on control and variability...
	Control valve exit noise and its use in valve sizing This technical paper by Alan Glenn briefly describes general aerodynamic noise generation and prediction and, in more detail, the IEC 60534-8-3 exit noise prediction. It further describes noise generation, propagation and transmission into the outside environment. Several sample cases are given....
	Controlling the power The requirement to test ever larger and more powerful pumps means that the control valve manufacturer has the challenging task of controlling both high pressures and flow rates simultaneously. This article describes how a valve was successfully designed to test an offshore water injection pump....
	CVA line to provide new benefits Rotork’s CVA line of electric valve actuators has been specifically designed to suit the requirements of all types of process control valves. The CVA delivers both linear and quarter-turn output and boasts technology that provides important benefits for the supply-chain, installers and end-users....
	Global outlook: Video Interview with OCV's Shirley Nelson During a recent trade show, Valve World on-line editor David Sear caught up with OCV's Regional Sales Manager Shirley Nelson, who kindly agreed to have her thoughts recorded on camera....
	How to reduce emissions from control valves? As concerns about environmental safety rise, global companies are paying increased attention to fugitive emissions from control valves. This is making rotary valves, which typically have lower gland emissions than rising stem valves, an attractive proposition, argues Metso Automation’s Vesa Lempinen....
	Measurement & Control Show in Gent In March 2008, Valve World headed off to Gent, Belgium, to attend a regional trade fair dedicated to the measurement and control sectors. We found several suppliers with plenty to tell about valves and other equipment used to provide effective control in process plants....
	Measurement of the fluid flow load on a globe valve stem Technical paper, in which the authors describe how a 2” plexiglas globe valve model was built to permit visual observation and measurements of flow-induced force on the stem. An extensive test program was conducted with varying key parameters such as disc position and operating conditions....
	Rotary globe valve – a novel innovation in flow control This technical article presents a new rotary control valve which combines a conventional linear globe body with a rotary stem. With a flow channel similar to that of standard globe valves, this valve can handle higher pressure-differentials than conventional rotary valves without cavitation....
	Space-saver PRDS: pressure reducing and desuperheating valve in one In most heating and process applications, saturated steam is a prerequisite. The main challenges for these applications are lowering costs yet boosting efficiency. This article by RTK Control Systems Ltd's Sam Samad shows how one valve can make this possible....
	Using computational fluid dynamics to predict cavitation Computational Fluid Dynamics (CFD) has been used to successfully model fluid flow in fields like aerospace and pump design. In this paper, Alan Glenn and Gifford Decker report how a high end CFD tool was used to numerically predict the point of incipient cavitation in complex valve configurations....

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