Upgrading FCC-unit valve controllers without disruption

In the fluid catalytic cracking (FCC) unit of a large refinery built in the 1940s in the US, a variety of control valve types and brands, along with their proprietary valve controllers, had been installed over the years. This had led to production inconsistency and disruption. The unit wanted to have one type of controller with multiple bracket designs to fit the wide variety of valves in the plant.

Simplifying control and improving consistency

The refinery decided to replace the existing controllers on approximately 250 existing control valves with advanced Neles ND9000™ intelligent valve controllers. The aim was to improve consistency of control and simplify the ongoing performance monitoring and maintenance of controllers in this FCC unit.

The first step in the replacement process was to perform a complete survey of existing controllers to determine the bracket and linkage requirements. The brackets were then designed, fabricated and provided in a kit with the appropriate linkage and installation instructions.

The installation of the new controllers was performed by the refinery staff on a rolling basis, based both on the condition of the existing controller and its availability for replacement, without disrupting the process. Shortly after the first positioners and installation kits had arrived,  our application specialists were present at the FCC unit to provide controller installation training.

Quick problem solving

During an early phase in the installation process, it was necessary to respond rapidly to correct a communication issue between the DCS and ND9000™. While it was not evident at the time as the focus was on corrective action, this problem quickly became an opportunity for all of the parties involved.

Upon completion of the project, the refinery shared that they had paid very close attention to the actions of us and our channel partners. The refinery’s conclusion was that the cooperative relationship shared by the three parties had resulted in much faster problem identification and corrective action than it had experienced earlier with other unrelated parties. The net result was a cost savings for the refinery, allowing it to stay on schedule with its process commissioning.

High performance and minimal disruption

The refinery was very pleased with this fast problem resolution and with the well-executed controller replacement program that had caused minimal disruption to its production. The ND9000™ controllers continue to perform consistently at a high level over a wide range of valve types on the cracking units. The refinery has since requested additional ND9000™ positioners to be used on several new units.

The Neles ND9000™ is an intelligent valve controller designed to operate on every control valve actuator and in all industry areas. This controller was selected as it guarantees end product quality in all operating conditions with its unique diagnostics and incomparable performance features. It is a reliable and future-proof investment when combined with lifetime support provided by asset management software.


Text originally published in 2014, and slightly updated in April 2022, due to the company name change to Valmet.

Written by Sari Aronen