Page 283 - Failure Analysis Case Studies II

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B type hosepipe
Fig. 1. Appearance of bursting hosepipes (arrowheads aim at openings).

3. Dissection of hosepipes

The hosepipes were dissected from the outer to the inner layers in order to study the charac-
teristics of bursting hosepipes. The results showed that:

(1) The steel wire layer was intact.
(2) In all A type hosepipes, there was only one opening in the inner rubber layer. Similar results
were obtained for most B type hosepipes except two, where two openings were observed.
(3) The opening in the inner rubber layer was situated in the outside of the bend near the metal
elbow adapter. The distance between the opening and the metal core is about 2.0-12.5 mm
(see Fig. 2).
(4) The openings in the inner rubber layer are circumferential, as shown in Fig. 2.
(5) No other defects were observed in the inner layers of the hosepipes.