A new innovation in electric actuator valves in the subsea process industry is set to disrupt the industry and replace conventional hydraulic cylinders.
The SVA R2 Subsea Valve Actuator from Bosch Rexroth has an integrated electric controller that offers precise motion control, condition monitoring and a safety spring, satisfying Safety Integrity Level, or SIL, 3 in accordance with IEC 61508 and IEC 61511 standards.
The actuator is said to be a world first, designed to minimise energy consumption and geared toward delicate ecosystems, reducing installation and operating costs. When the SVA R2 is used in subsea factories at a depth of up to 4 000 m, hydraulic pipes or power units are no longer required. The electric supply pipes already installed for sensors are adequate to ensure the reliable operation of the actuators.
Process systems’ operators have previously relied mainly on hydraulic cylinders to open and close subsea valves with a quarter turn and a defined force. With offshore installations like oil and gas production, these cylinders are supplied by a central hydraulic power unit with hydraulic pipes several kilometres long, using a great deal of energy to compensate for the cumulated losses and unable to control the movement with precision.
Plant engineers and operators relied on hydraulic cylinders because they are the only components to offer field-proven safety systems with a mechanical spring in a compact design. Conventional electric actuators do not have this safety function as a result of the size and weight requirements. Designs to ensure safety using subsea batteries can also not guarantee the reliable closing of valves over the required operating life of up to 25 years.
Bosch Rexroth explains that its team worked closely with suppliers and operators of offshore installations and international universities to develop its SVA R2. The new module comprises a pressure-compensated container incorporating an electric drive, a motion control system and a safety device – and can replace previously used hydraulic cylinders on a 1:1 basis. It requires only one cable for the power supply and communication and is designed to actuate valves reliably with the same power supply commonly used for subsea sensors. Switching to compact and safe electric actuators means that extremely long hydraulic pipes and associated power units and controllers are no longer required.
Designed for high volume production, the company asserts that the electronics for the motion control system have been proven to be robust and reliable. The SVA R2 is protected by a number of patents and is designed to operate for 25 years. The actuators for rotary adjustment complement the award-winning SVA L2 Subsea Valve Actuator for linear movements.
The actuator is also suitable for applications both below and above water such as hydrogen production, carbon dioxide storage and general applications in the process industry.