Rubber and plastics hoses — Assessment of ozone resistance under static conditions

ISO 7326:2016 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.

NOTE For hoses with built-in fittings from which it is not possible to take test pieces, the ozone resistance can be assessed on slabs in accordance with ISO 1431 1, using test sheets of the appropriate polymeric compound vulcanized to the same degree.