MIL-DTL-8794F
4.8.9 Collapse test (hose size -3 through -10 only) (see 3.5.6). A hose assembly when subjected to
collapse testing shall meet the requirements of 3.5.6. The following details shall apply:
a. The collapse test shall be conducted on a hose assembly that has been oil-aged as specified
in 4.7.1.2.
b. The hose assembly shall not be dried or washed after oil aging, and the test shall be
conducted within 1 hour after removal of hose from the oil-aging fluid.
c. A steel ball, with the diameter specified in table III and adequately perforated to prevent being
affected by a vacuum, shall be used as test specimen.
d. The hose assembly shall be bent over a form to the radius specified in table II and a vacuum
of 28 inches of mercury applied and held for 5 minutes, during which time the hose assembly
shall be rotated and re-bent over the form at 90° intervals throughout 360°.
e. With vacuum still applied, the hose assembly shall be straightened and held in a horizontal
position and gradually tilted to 30° in each direction.
f. The test is passed if the ball rolls through the hose assembly.
g. After release of the vacuum, the hose shall be dissected longitudinally and examined for
evidence of ply separation, blistering, collapse, or other damage (see 3.5.6.).
4.8.10 Bending and vacuum test (see 3.5.7). The bending and vacuum test shall be conducted on a
following details shall apply:
a. The hose assembly shall be bent over a form to the radius specified in table II and the OD
measured at the flattened section.
b. While still bent in this radius, a vacuum of 28 inches of mercury shall be applied to the hose
assembly and held for 5 minutes, during which time the hose shall be checked for additional
flattening.
c. After release of the vacuum, the hose shall be dissected longitudinally and examined for
evidence of ply separation, blistering, collapse, or other damage.
c. All sizes of hose shall not flatten or otherwise deform at any section in an amount greater than
10 percent reduction in OD (25 percent for size -32) before the vacuum is applied.
d. This test does not apply to hose sizes -40 and -48.
4.8.11 Elongation and contraction (see 3.5.8). The elongation and contraction shall be tested as
specified in ASTM D380 and meets as specified in 3.5.8. The following details shall apply:
a. Test specimens shall consist of three hose assemblies, each not less than 18 inches (45.7
cm) between fittings.
b. Test pressure shall be the hydraulic operating pressure specified in table II for the type and
size hose tested.
c. Average change in length of the three specimens, expressed in percentage of the original
length, shall be calculated and used as specified in 3.5.8.
4.8.12 Corrosion resistance test (see 3.5.9). A hose assembly subjected to the corrosion resistance
test shall meet the requirements of 3.5.9). The following details shall apply:
a. With the ends plugged, the hose assembly shall be immersed in a vertical position into a 2.5
percent aqueous solution of sodium chloride for a period of 5 minutes.
b. The hose assembly shall then be air-dried for 25 minutes at a temperature of 140± 5 °F (60°C
± 5°C).
c. This immersion and drying cycle shall be repeated for a total of 168 hours.
d. Upon completion of this test, the hose assembly shall be subjected to the applicable burst
pressure as specified in 4.8.13.
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