Underwater Linear Actuators and Motion Systems Explained

Linear actuators are also commonly referred to as linear drives, electric cylinders, or linear motion systems. In subsea and offshore contexts, they may be called subsea actuators or underwater electric actuators. NV Mechanics Design's products are often described as self-compensated subsea linear drives due to their integrated driver and encoder architecture.

NV Mechanics Design offers linear actuators rated to 3,000 msw (meters of sea water) and up to 6,000 meters depth. The Self-Compensated Linear Actuator is rated to 3,000 msw, while the Trunion 1000N and 60,000 N Force models are both rated to 6,000 m, making them suitable for deepwater and ultra-deepwater subsea deployments.

The product range covers axial forces from 1,000 N (220 lbs) up to 77,500 N (approximately 7,000 lbs). The Self-Compensated model delivers up to 1,500 N, the Trunion model scales from 1,000 N to 77,500 N, and the 60,000 N Force model provides up to 50,000 N, accommodating light-duty instrumentation through heavy-duty valve actuation tasks.

All actuators are manufactured from Stainless Steel 316 (SST 316) or Titanium, both of which offer excellent corrosion resistance in saltwater and aggressive subsea environments. Titanium is preferred for ultra-deep or weight-sensitive applications, while SST 316 provides a cost-effective solution for standard subsea and offshore deployments.

The Self-Compensated Linear Actuator features integrated RS422/RS232 serial communication with all driver and logic circuitry housed internally, enabling standalone position control. The Trunion and 60,000 N Force models use an external rotary resolver for position feedback, requiring an external driver and control logic supplied by the integrator.

All NV Mechanics Design actuators use Seacon underwater connectors, which are industry-standard subsea electrical connectors designed for reliable performance under high hydrostatic pressure. The Self-Compensated model additionally uses an MCBH8M subcon underwater connector with an 8-pin interface, with a 12-inch whip cable provided for integration.