Fina Antwerp Olefins chooses fireproofed Rotork actuators

Fina Antwerp Olefins chooses fireproofed Rotork actuators

15/01/2004

Rotork electric and Fluid System actuators are specified for the automation and expansion of the Fina Antwerp Olefins refinery.

The Fina Antwerp Olefins refinery has been the subject of a thorough revamp and expansion project known as NC2X, which is now in its final stages. The project has the objective to increase annual ethylene production capacity to 1.4 million tonnes whilst also introducing improved safety systems.

Rotork valve actuators are already used on the site, which was originally built fifty years ago. Therefore, IQ and AQ electric actuators, together with Fluid System actuators, mostly fitted with K-Mass fireproof coatings, were specified for the automation and expansion of the NC2 plant, which has been in operation since 1969. For the compressors, located at the beginning of the process, a special design was conceived to automate the large, previously manually operated emergency block (shut down) valves. These gate valves, in sizes up to 42, isolate and protect the main plant from the supply of product in the event of a gas leak or fire.

Due to the critical importance of the application to plant safety, the IQ actuator installations required customisation to comply with detailed specifications. This was successfully achieved with the involvement of Dirk Stroeckx (Fina), Chris DePaepe (Kellog, main contractor), Mike Gover (Rotork UK) and Frederik Van Acker (Prodim, Rotork's agent in Belgium).

The design ensures accurate remote valve position indication to enable the compressors to be safely shut down. Each valve spindle is fitted with an indication rod the same length as the valve size (42 inch valve = 42 inch indication rod). The rods are made of two materials in equal proportion - top half stainless steel, bottom half aluminium.

Each IQ actuator is equipped with a K-Mass coated covertube, twice the length of the indication rod, in the middle of which are attached three proximity switches in a 120 degree array, fitted in springed cover tubes so that they push against the indication rod to ensure positive contact throughout valve movement. These switches indicate aluminium but cannot "see" stainless steel, therefore providing three additional "valve 50% closed" signals independently from the actuator.

Dirk Stroeckx explains: "This system was required for additional safety and independent availability. We chose 50% closed indication as we don't want to wait until the valves are completely closed before tripping the compressors. Our experience with Rotork products has been good. Personally I think they are very reliable and of good quality. We are also very satisfied with the level of service provided by Prodim."