Engineers at Bosch Rexroth have developed an electric valve actuator (SVA R2) that can replace the hydraulic cylinders commonly used to open and close valves used in undersea oil drilling and recovery. The electric actuator is as compact and safe as hydraulic cylinders. It can operate for up to 25 years at locations 13,125 ft beneath the surface of the ocean without needing to change batteries or install ancillary hydraulics, pumps and hoses.
Until the new valve was developed, petroleum engineers relied on hydraulics to control oil flow in undersea applications. This required piping hydraulic fluid thousands of feet to the bottom of the ocean and back, which consumes a significant amount of power. But hydraulic cylinders were the only devices that could provide the necessary failsafe features in underwater applications. Providing the same level of safety with electric actuators (i.e., being able to quickly and securely close the valve in case of power outages and emergencies) was too complicated and expensive. Plus, batteries for electric valves could not be guaranteed for the valve’s 25-year operational life.
The new actuator includes an electric drive, motion-control hardware and a spring-based failsafe feature housed in a pressure-compensated container that lets it operate at depths of up to 13,125 ft (4,000 m). The actuator uses reliable, industrial and automotive components with proven track records of durability.
The field-proven safety feature lets the actuator meet Safety Integrity Level 3 (SIL 3) standards (IEC 61508 and IEC 61511). It was designed with oil and gas production in mind, but it will also work in systems that pump and transport CO2, H2 and water, and can be powered by the same power supply the actuator’s sensors rely on.