Quality Requirements for Ti-3Al-2.5V Annealed and Cold Worked Hydraulic Tubing

This paper presents the author's view of the items Grumman Aerospace considers the controlling factors in obtaining a high quality aircraft hydraulic fluid transmission system utilizing titanium alloy Ti-3Al-2. 5V tubing.

The discussion is divided into three separate areas of consideration. Tube length production is discussed in light of those processes or procedures which effect quality, and the test methods required to detect flaws. Tube shop tooling requirements are presented which are essential to the maintenance of the strength and quality levels imparted by the tube producer. Included is a theoretical description of the effects of ovality on impulse fatigue life. The third area considered describes the requirements for assembly and installation of the fluid transmission system into the using vehicle. The attachment fittings used in the Grumman F-14A aircraft, and the reasons for their choice are described.

In support of some areas of the discussion, actual test data is presented on the degrading effects of ovalization on the impulse fatigue life of Ti-3Al-2. 5V tubing. Data is also presented showing an increase in impulse fatigue life with increasing overpressurization.