Ensure Critical Valves are Healthy - Neles SmartSolutionsTM will

Published: 25th September 2009 | Issue 2

Everyone appreciates how important Partial Stroke Testing is for Emergency Shut Down Valves (ESD) and Emergency Vent Valves (ESV) not only for Insurance purposes but mostly for the safety of plant personnel and the plant.

Over the years, different methods have been tried to handle this e.g. pneumatic panels, mechanical jammers etc but most require the valve to be taken off line for the partial stroke test thus making the unit unavailable if an upset occurs. The operating integrity of any ESD/ ESV depends on the final control element-typically via a solenoidwith the valves remaining in the fullyopen/closed position until required to operate.

Extensive research by independentauthorities e.g. OREDA and also by Metso Automation have concludedthat the weakest link in the ESD/ESV package is the solenoid valve which could cause the valve to stick. To overcome this weakest link the Neles ValvGuardTM, one of the products from the SmartSolutionsTM range, was born. This Smart Device evolved from listening to customer needs to improve reliability of the ESD and increase safety of the plant and plant personnel. The Neles ValvGuardTM was designed to replace the solenoid valve - new or existing - and provide both overt and covert monitoring in the ESD in a live real time environment.

To test ESD/ESV valves utilizing traditional safety systems, operators have to shut down the process or extensive operator action is needed. Not with Neles ValvGuardTM. Now youcan reliably test valve performanceanytime without disturbing the process at all. And if an emergency signal occurs during testing, the Neles ValvGuardTM automaticallyby-passes the test procedure and performs the safety action.

The solution for testing using a solenoid and positioner has the problem that the weakest link is not checked to see whether it is still working. Other limitations of the solenoid/positioner combination are:
A) extra cabling is required i.e. control and power-with theNeles ValvGuardTM only 1 cable is required to 1 unit
B) generally movement is limited to 10-30 % travel - with the Neles ValvGuardTM testing can be carried out from 5 to 100% movement
C) some positioners have no memory so any diagnostics have to be stored elsewhere - with the Neles ValvGuardTM having its own onboard process or all the diagnosticsare stored until required. As the Neles ValvGuardTM uses open architecture, dedicated software may not be required.
D) testing has to be initiated by someone. Because Neles ValvGuardTM is a smart processor controlled device, monitoring and testing procedures are not dependent upon operator interaction. This minimizes any consequences that might have occurred due to human error while dramatically increasing the reliability of your system.
E) the Neles ValvGuardTM carries out a pneumatics test as well as a partial stroke test and so spurious trips can be significantly reduced.

Automated On-Line Testing

Neles ValvGuardTM allows you to an on-line testing sequence based on your specific process needs - anywhere from every few minutes up to only once a year. There’s no extensive testing management needed either. Valve status is immediately reported back to you as "OK", "Testing" or "Alarm."

Neles ValvGuardTM is uniquely designed to lower your operating costs and deliver fast payback. You can expect savings in several important areas because Neles ValvGuardTM requires fewer valves to meet your SIL 3 requirements, less piping and cabling, fewer testing hours, less managing and reporting time, less maintenance, simpler reporting procedures, and lower engineering and procurement costs.

Predictive Maintenance
Because the condition and performance of the valve is known at all times, maintenance periods can be extended and unnecessary repairs avoided. All valve test reports can be forwarded to maintenance personnel. Spare parts management can be optimized. And service agreements with Metso Automation can be arranged for periodic diagnostics work and remote analysis.
High Reliability Valve Components
Metso Automation valves are engineered to deliver optimum performance in ESD/ESV applications. The unique metal seating technology has been proven for over 30 years i some of the most difficult processes. The range of Neles SmartSolutionsTM products consist of the following

Neles FieldCareTM

Field device asset management software with condition monitoring capability supports open and standardized FDT/DTM technology.

Neles ND9000®

Intelligent valve controller that provides a unique combination of optimum performance and 2nd generation predictive diagnostics.
Neles ValvGuardTM Cost-effective partial stroke testing solution for ESD and ESV valves fulfilling IEC 61508 and IEC 61511
standards.

Neles SwitchGuardTM

Intelligent controller for process critical switching and high-cycle applications; the latest addition to
the Neles SmartSolutionsTM product range. For further information on any of the Neles SmartSolutionsTM range
please contact your local Metso Automation Office.

Valmet UK Ltd