Subsea actuators are motion-control devices engineered to provide controlled linear or rotary movement, positioning, and force in underwater environments. Used across ROVs, AUVs, subsea production systems, scientific instruments, and marine robotics, these systems support valve operation, tooling, sampling, payload positioning, buoyancy adjustment, and manipulator control.
This page features leading underwater actuator manufacturers, offering electric, hydraulic, linear, rotary, servo, stepper, and brushless DC motor-based designs.
Read the Technology Overview
If you design, build or supply Underwater and Subsea Actuators, create a profile to showcase your capabilities and connect with visitors who have an active requirement for your solutions.
Subsea actuators play a crucial role in a wide range of underwater and subsea operations. These devices are designed to provide precise control over movement, positioning, and force in demanding marine environments. Underwater actuators are integral to applications such as remotely operated vehicles (ROVs), subsea production systems, and underwater robotics, where reliable and efficient motion is essential.
Subsea environments present unique challenges, including high pressures, low temperatures, and corrosion from saltwater exposure. To meet these demands, subsea actuators are built using advanced materials and technologies that ensure long-term performance and durability. This page provides an overview of the different types of underwater actuators and the technologies that enable their functionality in these challenging environments.
A ROV actuator is used to control manipulators, grippers, payload mechanisms, camera positioning units, and tooling interfaces on remotely operated vehicles. In AUVs, a submersible actuator may support buoyancy control, sample collection, payload deployment, or automated adjustment of onboard mechanisms.
Subsea electric actuators are used to operate valves, chokes, hatches, and flow-control equipment in offshore oil and gas infrastructure. A subsea electric valve actuator provides precise remote operation for underwater production systems, while a subsea hydraulic actuator may be used where higher force output is required.
Subsea actuators support tooling used for cutting, clamping, connector mating, mechanical adjustment, and seabed interaction. These systems require repeatable motion, controlled force, and reliable operation under pressure.
Actuators are used to adjust sonar heads, cameras, sampling arms, lighting systems, sensor packages, and other payloads on subsea platforms. This allows operators or autonomous systems to reposition instruments without recovering the vehicle or equipment.
Subsea actuators can control water samplers, sediment corers, biological collection tools, and seabed monitoring instruments. These applications often require precise motion, low power consumption, and dependable long-duration operation.
Boat actuator systems may be used for hatch control, trim adjustment, steering support, lifting mechanisms, and other motion-control functions on surface vessels or shallow-water marine equipment. While these systems may not be rated for deep subsea use, related marine actuator designs can support equipment operating below the waterline, in splash zones, or in exposed saltwater environments.
There are several types of actuators used in subsea applications, each serving specific functions based on the requirements of the operation. These include waterproof linear actuators, rotary actuators, and other specialized designs that utilize components such as stepper motors and brushless DC motors to deliver precise movements.
U-Series underwater and subsea actuators by Ultra Motion
Linear actuators are widely used in subsea applications where linear motion is required. These actuators convert rotational motion into straight-line movement, allowing them to control the position of valves, clamps, and other components in subsea systems.
For applications that require robust force and high precision, oil-filled designs are often implemented to ensure reliable performance under extreme pressure conditions. Linear actuators are integral to underwater systems that demand exact positioning and motion control.
AU Series subsea linear actuators by Ultra Motion
Rotary actuators are used when rotational motion is necessary. These actuators are common in subsea production systems, where they control the rotation of valves, hatches, and robotic arms. Rotary actuators can be powered by various technologies, such as by a stepper motor or brushless DC motor, both of which offer smooth and precise rotation.
The use of rotary actuators in underwater applications ensures accurate and repeatable motion control, making them essential for operations in marine environments.
T3U subsea rotary actuator by Ultra Motion
Subsea valve actuators are employed in oil and gas production, underwater robotics, and other marine operations. These actuators must be capable of precise control, often utilizing servo actuators to achieve the desired motion.
Pressure compensated designs and electric actuators ensure reliable performance in extreme underwater conditions. Subsea valves, paired with subsea electric actuators, contribute to the safe and efficient management of subsea production systems.
Subsea actuators often rely on different motor technologies to achieve their performance goals. Two of the most common types of motors used in subsea applications are stepper motors and brushless DC motors.
Stepper motors are known for their ability to provide precise and controlled movement in discrete steps. This makes them ideal for applications where exact positioning is required, such as in ROVs or subsea manipulators. The advantage of stepper motors in marine actuators lies in their reliability and ability to operate without the need for complex feedback systems.
Brushless DC motors are another widely used motor type in subsea applications. These motors offer higher efficiency and greater reliability compared to their brushed counterparts.
By eliminating brushes, brushless DC motors reduce the risk of mechanical wear, which is crucial in subsea environments where maintenance can be difficult. These motors can be found in both rotary actuators and submersible linear actuators, where long-lasting performance and low maintenance are priorities.
Subsea applications frequently use BLDC motors and servo motors for their high efficiency and precision. Servo actuators deliver precise control for demanding underwater tasks.
BLDC controllers optimize performance by maintaining efficiency, while dc brushless motor systems provide durability in high-pressure environments. These technologies are indispensable for subsea robotics, where brushless motors enhance movement precision and reliability, even under harsh marine conditions.
Underwater actuators often incorporate additional features to enhance their performance in underwater environments. One of the critical requirements for these devices is absolute position feedback, which allows operators to know the exact position of the actuator at all times. This capability is essential for subsea systems that require real-time monitoring and control of actuator movements.
Another important feature is the use of oil-filled housings. By filling the actuator housing with oil, these devices are better able to withstand the intense pressure found at subsea depths. The oil also provides a level of protection against corrosion and helps maintain consistent actuator performance over time.
Control systems such as a stepper motor controller are integral for managing the movements of subsea actuators. These controllers provide the precision required in underwater systems.
A BLDC motor controller can be used to optimize the performance of brushless motors in subsea applications. Additionally, contactless absolute position feedback systems enable real-time monitoring of actuator positions, a critical feature for maintaining control in deep-sea environments.
Marine actuators are commonly found in subsea robotic systems, where they play a vital role in controlling movement and force. These actuators are designed to be compact yet powerful, allowing them to fit into tight spaces while still delivering the necessary torque or linear force. In ROVs and other underwater vehicles, marine actuators are responsible for manipulating robotic arms, adjusting buoyancy systems, and operating grippers.
By using subsea actuators with advanced motor technologies and specialized features, subsea robotic systems can perform complex tasks in hostile marine environments. These actuators contribute to the efficiency and effectiveness of subsea operations, allowing for remote intervention and control in areas that are difficult or impossible to access by human divers.
Searching Companies & Products
Subscribe to the Weekly eBrief
The latest engineering and technical developments straight to your inbox - join thousands of engineers who receive it.
