ISO 7233-2016 pdf download.Rubber and plastics hoses and hose assemblies – Determination of resistance to vacuum.
3.2 Smooth, solid ball (for method A), with a diameter equal to 0.9 fines the bore of the hose under test, rounded down to the nearest whole millimetre.
5.3 Two transparemt airtight plates ((or method B), for sealing each end 01 the hose. One of the plates shall permit attachment of the vacuum pump to the hose, while allowing internal visual inspection of the hose during the text
6 Test pieces
lithe complete hose or hose assembly Is more than 1 m long, each test piece shall consist ala minimum length of hose, dear of the end httings. of 1 rn If the complete hose or hose assembly Is less than 1 m long, the complete length shall be used.
7 (:ondllioning of test pieces
No tests shall be carried out within 24 h of manufacture, Test pieces shall be tonditioned at the appropriate temperature in accordance with ISO 23529 for at least 3 h before testing.
ThIs 3 h period may form part ol the minimum period of 24 h between manufacture and testing.
8 Test pressure
The internal pressure to which the hose is subjected to for the duration of the test shall be that stated in the product standard for the hose under text as being the minimum internal pressure Which the hose is required to withstand.
9 Procedure (method A)
Lay out the hose as straight as possible on a flat surface and blank air one end to form an airtight seal. Insert into the hose a smooth. iolld boll (5.2) and then connect the open end f the hose to a vacuum pi.isnp and gauge. Reduce the pressure in the hose within 60s to the required test pressure and maintain this pressure for the required period, which shall not be less than 10 mm.
While the test pressure Is being maintained, examine the hose externally For any signs of indentation or collapse and then tilt the hose to permit the solid ball to traverse the full length olthe hose to check for any obstructions caused by Internal deformation or delamination.
10 Procedure (method B)
Lay out the hose as straight as possible on a flat surface and lit transparent airtight plates (5.i) to bath ends of the hose, one of which shall then he ccmnccted to a vacuum pump and gage. Reduce the pressure in the hose within 60 s to the required text pressure and maintain this pressure for the required period, which shall not be less than 10 miii.
While the test pressure Is being maintaim.’d, examine the interior or the hose through one or the transparent plates by means of illumination supplied through the transparent plate at the other end of the hose for signs of delamination or blistering of the lining. Also examine the exterior of the hose for signs of indentation or coUapse.
11 Procedure (method C)
Lay out the hose as straight as posuble on .1 flat surface. blank off one end to form an airtight seal, ,and connect the other end to a vacuum pump and gauge.ISO 7233 pdf download.