Braided Hose Rupture
Background: Drop in internal pressure was experienced during operation due to failure of the braided hose. This hose operated at a discharge pressure in the order of 150-250 psig with dynamic fluctuations.
Figure 1: Visual Inspection of As-Received Braided Hose Showing Longitudinal Crack and Mechanical Damage on the Surface
Figure 2: Fractography of Crack Observed on the Braided Hose Showing Typical Fatigue Failure Features
Summary: The braided hose failure was associated with crack formation and propagation under fatigue. In the course of the investigation it was determined that the hose had been misaligned and exposed to undesirable compressive loading during installation, which correlated with the buckling of the corrugated tube section. The mechanical surface damage observed indicated interaction between the corrugated section and the braided wire jacket during buckling. This interaction facilitated local thinning, bulging, and crack initiation and propagation under dynamic operational pressure conditions.
Takeaway: Improper installation, permanent deformation of material can significantly lower the fatigue strength of the component and cause premature failures.
Takeaway: Improper installation, permanent deformation of material can significantly lower the fatigue strength of the component and cause premature failures.