Fisher Controls International Inc., a division of Emerson Process Management, has added “Performance Diagnostics” (PD) and diagnostic interpretation services to its Fieldvue DVC5000 and DVC6000 series instruments. The on-line valve diagnostics further expand the ability of Fisher valves and the PlantWeb(R) digital plant architecture to deliver information on valve performance to people who run the business. The services help users apply the information to increase plant availability and reduce cost of ownership. When used in combination with AMS ValveLink(R) software, PD capabilities allow users to determine key valve-performance indicators such as dead band and friction (sliding stem) or torque (rotary) – while the control valve is on-line and in service. Traditional approaches to gathering these performance indicators required taking the valve out of service, or connecting portable testers at the valve. The in-service, on-line monitoring provides a true indication of control valve performance in a predictive manner. If required, more extensive off-line diagnostics may be conducted to completely access and outline required maintenance.