ISO 7326:2006 specifies five methods for determining the ozone resistance of the outer covers of hoses:
method 1, for bore sizes up to and including 25 mm, carried out on the hose itself;
method 2, for bore sizes greater than 25 mm, carried out on a test piece from the hose wall;
method 3, for bore sizes greater than 25 mm, carried out on a test piece from the cover;
method 4, for all bore sizes, carried out on the hose itself;
method 5, for all bore sizes, carried out on hoses that are expandable, for example textile-reinforced hoses.
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