Tubing, piping, and hose – and the fittings that connect them – are the circulatory systems of today’s aircraft. Carrying high-pressure hydraulic fluid to and through critical subsystems and components such as flight control actuators, engine-driven pumps, auxiliary pumps, electric motor pumps, power transfer units, and more, these components are key to an aircraft’s power and flight control. Yet, despite the increased complexity of hydraulic systems today, fluid leakage is a nagging cause for re-work and unscheduled maintenance.
But what if there was a better way? What if an innovative approach offered lower installation time with a visual indicator for a leak-free connection?
Enter the new visual torque indication, a patent-pending family of fittings that offers these benefits and more from the Stratoflex Products Division of Parker Aerospace, the industry leader in fluid conveyance systems and components.
Current state: uncertainty of connection, time-consuming installation process
Plumbing and maintaining the hydraulic system of a large commercial aircraft can be a daunting and time-consuming task. A typical commercial transport contains hundreds of feet of tubing and thousands of fittings and fitting connections1.
Today, installers use torque wrenches and specialized torque procedures to secure system connections and apply a torque stripe to indicate completed assembly. However, the large number of connections and challenging installation requirements lead to improper connections, with no means of detection until the system is pressurized. Should the connection leak, additional time must be taken to locate the improper connection, clean hydraulic fluid spills, and re-torque or replace the leaking assembly.
Connection innovation: Parker visual torque indication fittings
With patent-pending design features, visual torque indication fittings offer significantly lower installation time for connections while providing an immediate, visual verification of a properly assembled connection. These benefits combine to support the increased production rates required by aircraft OEMs for the demanding aerospace market.
Developed from proven Parker fluid connection technology and qualified to industry and customer requirements, visual torque indication fittings offer:
- Visual indication: verifies proper connection, eliminates torque striping and facilitates fast, error-free inspection
- Unique thread design: provides faster connection time and is tolerant to misalignment during assembly
- Dual seals: provide redundancy against system leakage and associated re-work
- Standard wrench assembly: no specialty tools or torque procedure needed
Visual torque indication fittings are designed for operating pressures for today’s hydraulic systems. Visual torque indication fittings utilize aerospace materials (corrosion-resistant steel, aluminum, titanium) for sizes -4 through -24.
For additional information on Parker Aerospace systems and capabilities, please visit our website.
This post was contributed by Jonathan Golightly, senior engineer, and Scott Pearson, division engineering director, of Parker Aerospace’s Stratoflex Products Division.