Inductive sensors in subsea applications

Equipment operating in subsea environments must be able to withstand the unique challenges presented by extreme pressure, low temperatures and corrosive saltwater.  One example is gate valves, which play a critical role in controlling the flow of fluids such as water, oil and other liquids in pipelines and wellheads on the sea floor. Like their marine counterparts, they operate by moving a gate or wedge up and down to start, stop and isolate fluid.

Rotary actuators for control of the gate valve position

Since manual intervention is impossible in deep-sea environments, subsea gate valves rely on rotary actuators for operation. These actuators convert energy into rotational motion, enabling the opening, closing or positioning of the valve. Due to their high power-to-size ratio, hydraulic actuators are the most common in subsea operations.

The role of inductive sensors in rotary actuators

Subsea rotary actuators incorporate submersible rotary inductive sensors to provide precise, non-contact position tracking. These sensors detect the position, angle or rotation of the actuator, offering crucial feedback for controlling the valve’s position.  Inductive sensors are particularly suited for subsea use due to their ability to operate in harsh, high-pressure environments without direct contact with moving parts.

Benefits of inductive sensors in subsea actuators

The properties of inductive sensors make them ideal for subsea applications. This includes:

1. Non-contact sensing: no physical contact is required between the sensor and the moving part, reducing wear and tear.
2. Hermetically sealed: inductive sensors can be completely sealed within pressure-resistant, corrosion-proof housings, ensuring long-term reliability.
3. Pressure tolerance: the sensors are designed to operate reliably at depths of 3000 metres or more.
4. Immune to contaminants: unaffected by water, oil or debris present in a subsea environment.

Further applications of inductive sensors in subsea actuators

As well as gate valve position sensing, inductive sensors are also found in a range of other subsea actuator applications where precision, reliability and feedback are critical for operational success. This includes:

1. ROV manipulator arms: inductive sensors enable position feedback for the rotational joints of underwater robotic arms.
2. Subsea manifolds: sensors detect the position or movement of valve stems, pistons and actuator rods, which is vital for ensuring that valves connected to subsea manifolds are correctly opened or closed.
3. Blowout Preventers (BOP): inductive sensors are critical for tracking, monitoring and verifying the position and movement of key components, such as rams and valves, to ensuring the BOP can successfully seal the wellbore during a well control event.
4. Subsea winches and lifting systems: inductive sensors track the movement of actuators that control lifting arms, gripping devices or other linear movements within winches and lifting system.

Inductive sensors play a vital role in ensuring the safety, reliability, and operational efficiency of subsea actuators. Their ability to provide precise, non-contact position tracking in extreme underwater environments makes them indispensable for controlling critical equipment such as gate valves, ROV manipulator arms, subsea manifolds, blowout preventers (BOPs), and winches.

If you're looking to enhance the performance and reliability of your subsea equipment, contact us today to learn more about our range of submersible sensors for the most demanding underwater applications.