Hydraulic Helical Spline Actuator
A compact, maintenance-free subsea hydraulic actuator using a helical spline mechanism to deliver extremely high torque for quarter-turn offshore and deep-water valve operations.
The Hydraulic Helical Spline Actuator is engineered for reliable, high-performance valve control in the most demanding offshore and subsea environments. It utilizes a robust helical spline mechanism that converts linear hydraulic motion into powerful quarter-turn rotary torque, making it ideal for subsea ball valve applications.
Designed for both single-acting (spring return) and double-acting configurations, the actuator features a fully pressure-balanced design with an integrated compensation system. This allows safe and consistent performance at extreme subsea depths.
The actuator is built with redundant sealing systems and an elastomeric environmental seal to completely prevent seawater ingress. This ensures long-term durability, corrosion resistance, and maintenance-free operation throughout its design life.
For safety-critical operations such as Emergency Shutdown Valves (ESDV) and High-Integrity Pressure Protection Systems (HIPPS), the actuator supports fast stroking and SIL-3 functional safety integration. It also includes a subsea ROV override interface, allowing manual intervention without displacing internal hydraulic fluid.
Each actuator is supplied fully integrated with matching valves to simplify installation, reduce commissioning time, and ensure optimal field performance in offshore oil and gas production systems.
Main Features
- Helical Spline design for quarter-turn operation (e.g. subsea ball valves)
- Compact design engineered for minimal footprint and weight
- 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
- Suitable for ESDV and HIPPS applications where fast stroking is requested
- ROV override interface for local subsea intervention
- No fluid displacement during ROV intervention
- Redundant sealing on all dynamic sealing areas
- Elastomeric environmental seal to prevent seawater ingress
- Integrated ATV relief valves, qualif
- 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
- 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
- Diver or diverless retrievable configuration
- Mechanical clutch to aid subsea deployment (retrievable version)
- Custom Actuator Retrieval Tool (ART) interface
- 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
- High torque output in a compact design
- Field-proven technology with a large installed base
Technical Data
Applications
Configuration
Product Range
Design Pressure
Temperature Range
Water Depth
- Up to 3048 m (10.000 ft)
- Greater Depth upon application
Compensation System
Manual Intervention
Quality Controls
QL-1 or QL-2
PSL-3, PSL-4
Materials
Electric actuation