February 2013 Q Plus BV was invited to study the engineering and production for 84 linear pneumatic actuator-sets for damper control to be supplied to three refineries in Siberia.
The main challenge was to design reliable actuators in both in/out and proportionally regulated versions able to work just above -49°C on the coldest location. This required ultra low temperature seals for all components and metal scrapers on piston-rod to remove accumulated ice. Due to the required testing temperatures of -60°C for the electronic components, it was decided to use heated cabinets for one location.
The 17 different models of actuators ,with diameters of Ø100, Ø125 and Ø160mm and strokes up to 300mm, have integrated safety elements such as lock-up valves to hold the actuators in position in case of low system pressure, and tendency valves to ensure slow closing in case of a complete plant pressure fail. To minimize sizes and weight of the actuators the use of mechanical springs and integrated manual override was studied but avoided, and SS pressure vessels with return air (or nitrogen) were used for safety. Feedback signals were realized under Hart protocol for the regulated actuators and proximity switches for the open close actuators. Materials used were SS and anticorodal aluminum with excellent low temperature brittleness coated with a white polyurethane paint system to ensure low temp flexibility for corrosion protection.
In four months time the development and final customer approvement were realized, including 3D drawings, schematics and installation, erection and maintenance manuals in both English and Russian language. The actuators were supplied under Atex and Gost-R certificates. Due to the tight given delivery time the total assembly of all 84 actuators was done in 2,5 weeks. The final shipping volume was around two 40-foot containers.
