Rotork receives big actuator order

Rotork has received a substantial order for its pneumatic actuators, the company set to supply 220 of them to the NASR Phase II Full Field Development Project in the UAE.

Awarded by Hyundai heavy industries, the order includes spring-return pneumatic actuators to operate 30” and 36” class 1500 ball valves. Specifications state that the maximum actuator output torque at a design pressure of 9.4 bar should not be in excess of 90% of the valves’ maximum allowable stem torque (MAST).

The huge force required to compress the spring means the above requirements are actually beyond the performance limits of the standard range of Rotork GP pneumatic actuators. This pushed Rotork’s R & D department to create an innovative solution.

“Rotork engineers added a second pneumatic cylinder, mounted between the GP scotch yoke centre body and the spring-return cylinder,” according to a statement from the company. “Both cylinders are pressurised in the same direction at the same time, so one delivers torque for valve movement, satisfying the valve MAST requirement, whilst the other independently applies the torque to compress the spring.”

The subsequent actuator is the largest GP350 actuator built so far, with a total length of 8.5 metres and a weight of 19 tonnes.

The NASR Phase II Full Field Development project aims to increase the oilfield’s production capacity from 22,000 barrels per had (BPD) up to 65,000 BPD.