Electric Servo Subsea Linear Actuators Explained

Axial force output ranges from 1,000 N (220 lbs) on the compact self-compensated model up to 77,500 N (approximately 7,000 lbs) on the Trunion series, and 50,000 N on the 60,000 N Force model — covering light valve actuation through heavy-duty subsea industrial operations.

All subsea linear actuators in this lineup use brushless motors. Brushless designs are preferred for underwater use because they offer higher reliability, longer service life, and reduced maintenance requirements compared to brushed alternatives — critical advantages in inaccessible subsea environments.

Self-compensated models feature integrated 30-bit absolute encoders on the output shaft, retaining position data between power cycles with 14-bit resolution per turn. The Trunion and 60,000 N Force models use a rotary resolver on the motor shaft for precise external position feedback.

The self-compensated actuators support RS422 (RS485 duplex on 4 wires) and RS232 serial communication at 19,200 baud. Parameters including status broadcast frequency and virtual limit switches are configurable and stored in internal EEPROM, allowing flexible integration with ROV control systems.

The higher-capacity models — Trunion 1000N and Linear Actuator 60,000 N Force — are available in Stainless Steel 316 (SST 316) or Titanium. Both materials provide excellent resistance to saltwater corrosion, making them well-suited for long-term deployment in offshore and deep-sea environments.

Power requirements vary by model. The self-compensated linear and rotary actuators operate on 24 VDC. The Trunion 1000N model supports 24 VDC, 48 VDC, and 230 VDC, while the 60,000 N Force actuator is designed for 230 VDC — accommodating a range of ROV and subsea power system configurations.