Hydraulic Linear Actuator

A high-performance subsea hydraulic linear actuator designed for deepwater gate-valve control, offering compact design, pressure-balanced operation, and SIL-3 safety capability.

The Subsea Hydraulic Linear Actuator is engineered to provide reliable and precise valve control in extreme offshore and deepwater environments. Developed for direct linear motion applications such as Through-Conduit Slab Gate Valves, this actuator features a compact, weight-optimized structure that minimizes subsea footprint and simplifies installation.

It is available in both single-acting (spring-return) and double-acting hydraulic configurations, allowing flexibility for various fail-safe requirements including Fail-Close, Fail-Open, and Fail-As-Is operations. The pressure-balanced design with an integrated compensation system ensures consistent performance at ultra-deepwater depths.

For long-term reliability, the actuator is equipped with redundant dynamic seals and an external elastomeric environmental seal that prevents seawater ingress. Its robust internal mechanism is built for long service life with minimal maintenance.

The actuator includes an ROV override interface for local subsea intervention and optional manual handwheel operation for diver-assisted handling in shallow waters. A local mechanical position indicator is standard, while optional limit switches or continuous transmitters are available for remote monitoring.

Designed to meet demanding international subsea standards, this actuator is suitable for safety-critical applications such as HIPPS and ESDV systems. It supports integration into SIL-3 rated functional safety architectures and is compatible with all-electric subsea actuation solutions where required. Its fast stroking capability, long design life, and proven subsea performance make it a dependable solution for modern offshore production systems.

Main Features

  • Linear design for direct linear motion (e.g. subsea Through Conduit Slab Gate valves)
  • Compact, weight-optimized construction for minimal subsea footprint
  • Robust and simple internal mechanism
  • Supplied fully integrated with its corresponding valve for optimal performance and reduced installation complexity
  • Spring return (single acting), or double acting hydraulic operation
  • Pressure-Balanced design with integrated compensation system, suitable for ultra-deep installation
  • Fast stroking capability suitable for ESDV and HIPPS applications
  • ROV override interface for local subsea intervention
  • Redundant sealing on all dynamic sealing areas
  • Elastomeric environmental seal to prevent seawater ingress
  • Local mechanical position indicator
  • Design validation to API 17D / API 6A or API 6DSSX
  • Proven up to Technology Readiness Level (TRL 7) with extensive subsea experience
  • SIL-3 capable for integration into functional safety functions
  • Long design life, maintenance-free operation

Options

  • Custom design or input supply pressure according to project requirements
  • No-Compressing spring configuration during ROV intervention
  • Wide selection of hydraulic connectors, including quick-couplings and hot-stab
  • Remote position indicators: continuous transmitters and/or limit switches
  • Wide selection of electrical connectors
  • ROV interface available in multiple orientations
  • ROV Bucket extension
  • Local position indicator extension
  • Drop-in manual torque tool with handwheel for diver operation (shallow water applications)
  • Pressure protection cap
  • ROV bucket debris protection cap
  • Client specific Type Approval or Design Validation test
  • PED
  • Painting according to Customer Specification

Benefit

  • Comprehensive range of sizes
  • Ideal for HIPPS and ESDV applications
  • Field-proven technology with a large installed base

Technical Data

Main Design Standard
API 17D, API 6DSSX, ISO 13628-4

 

Applications

Subsea T.C. Slab Gate Valve

 

Configuration

Single acting (Fail Close / Fail Open) or Double Acting (Fail-As-Is)

 

Product Range

  • From 20 to 500 mm stroke
  • From 5.000 N to 5.000.000 N output thrust

Design Pressure

Up to 345 bar (5.000 psi)

 

Temperature Range

-10°C ÷ +70°C

 

Water Depth

  • Up to 3048 m (10.000 ft)
  • Greater Depth upon application

Compensation System

Individual Close system (standard), individual open or common shared system

 

Manual Intervention

API 17H / ISO 13628-8 ROV Interfaces from Class 1 to Class 7, or Custom input torque / interface according to project requirements

 

Quality Controls

API 6DSS
QL-1 or QL-2
API 17D
PSL-3, PSL-4

 

Materials

Selection of high strength and high corrosion resistant materials, resulting from long experience, selected in accordance with customer requirements

 

Electric actuation

ATV operators are suitable for electric actuation by drop-in All-Electric Subsea Actuator
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