Overview
ISO 22089:2009 - "Aerospace - Hydraulic power transfer units - General specifications" defines the general requirements for hydraulic Power Transfer Units (PTUs) used in aerospace applications. The standard covers both uni-directional and bi-directional PTUs and is intended to be applied together with a purchaser’s detail specification that captures application-specific technical, test, reliability and quality requirements. ISO 22089:2009 addresses design, functional, strength, installation, maintenance, qualification and test provisions for PTUs that transfer hydraulic power between independent hydraulic systems without transferring fluid.
Key Topics
The standard contains detailed requirements and test criteria across these technical areas:
- Functional requirements
- Hydraulic fluid compatibility, rated temperature, acoustic noise, endurance
- Pump/motor displacements, pressures (pump, motor, case drain), flows, leakage, speed/direction, efficiency, control
- Design and construction
- Dimensionally critical components, seals, lubrication, balance, drive shaft, materials, corrosion protection, castings
- Strength and load
- Pressure loads, proof and burst pressures, pressure impulse (fatigue), port strength, structural loads
- Installation and maintainability
- Mounting, ports, dimensions, mass, maintainability features, service life and storage
- Verification and quality
- Acceptance tests, qualification tests, test-stand requirements, inspection responsibilities, reliability and quality assurance provisions
- Classification and terminology
- Definitions for PTU types, ports, purchaser/supplier roles and normative references
Applications and Users
ISO 22089:2009 is used where reliable transfer of hydraulic power is required between independent hydraulic systems in aerospace platforms. Typical users include:
- Aircraft manufacturers and system integrators specifying PTUs within hydraulic system designs
- Equipment suppliers and PTU manufacturers responsible for design, production and qualification
- Modification centres and maintenance organizations referencing test, installation and maintenance requirements
- Certification and quality teams that need standardized acceptance and qualification criteria
Applying ISO 22089:2009 helps ensure PTUs meet consistent safety, performance and airworthiness expectations and supports system redundancy, load sharing and fault-tolerant hydraulic system designs.
Related Standards
ISO 22089:2009 references and is intended to be used alongside other aerospace and fluid-system standards, including (examples):
- ISO 7137 - Environmental conditions and test procedures for airborne equipment
- ISO 11218 - Cleanliness classification for aeronautical fluids
- ISO 3323 - Marking to indicate approved hydraulic fluid
- ISO 7320 - Couplings for fluid systems
- Various ISO environmental and materials process standards
For suppliers and purchasers drafting a detail specification, ISO 22089:2009 provides the general framework and test program baseline for aerospace hydraulic PTUs.