ISO 7233:2021 specifies three methods for determining the resistance to vacuum of hoses and hose assemblies manufactured from plastic or rubber. Applicable dimensions of hoses for each method are as follows:
— method A for hoses of nominal size up to and including 80;
— method B for hoses of nominal size greater than 80;
— method C for hoses of all dimensions. If not otherwise specified in the product standard, method C can be used as an alternative to methods A and B.
Methods A and B can also be used to check the adhesion of the lining to the reinforcement (delamination) in a length of hard-wall hose or hose assembly.
