MIL-DTL-26521L
4.6.3.4 Proof pressure (see 3.6.7). The hose assembly proof pressure shall be tested in accordance
with ASTM D380 and meet the requirements of 3.6.7.
4.6.3.5 Burst resistance (see 3.6.8). Hose assembly burst pressure resistance shall be tested in
accordance with ASTM D380 and meet the requirements of 3.6.8.
4.6.3.6 Hose assembly static dissipation test (see 3.6.3). The electrical resistance when tested in
accordance with ISO 8031 shall meet the requirement of 3.6.3. The following detail shall apply; the hose
assembly shall be measured from coupling using a 500 volt source.
4.6.3.7 Low temperature flexibility (see 3.6.5). Hose assembly when subjected to the low
temperature flexibility testing shall meet the requirements of 3.6.5; the following details shall apply:
a. The flexibility tests shall be carried out with an empty length of hose, the length of which is
calculated as follows:
Hose Length = 3.142D + 4d
Where:
D = Test drum diameter
d = Hose ID
b. Determine the external test drum diameter based on the hose diameter using table VI.
TABLE VI. Test drum external diameter in relation to hose diameter.
Test drum external
Hose ID
diameter
(d) ± .06 (1.52)
(D)
inch (mm)
inch (mm)
2.00 (50.8)
20 (508)
2.50 (63.5)
25 (635)
3.00 (76.2)
30 (762)
4.00 (101.6)
40 (1016)
c. Test samples shall be preconditioned at -40ºF (-40°C) for at least 24 hours prior to testing.
d. Attach the hose to the test drum with the clamp as shown on figure 4.
e. Place the test drum and hose specimen in a cold box/bath to keep their temperature at -40ºF
(-40°C).
Note: The test drum and specimen for hoses with inside diameters of 3 inches (76 mm) and
smaller shall be kept in the cold box/bath during the test to ensure the test temperature is
maintained. For the hose with inside diameter of 4 inches (101 mm), the test drum and
specimen must be at the test temperature but may be removed from the cold box/bath for
the test procedure. In this case the test must be initiated within 30 seconds of removal from
the cold box/bath.
f. Rotate the test drum using a torque wrench with a dial indicator. The drum shall be rotated
180° within 10 seconds.
g. Record the maximum registered torque required to bend the hose around the test drum.
Report the test result in foot-pounds (lb-ft). Results shall be submitted to the contracting
activity in first article test results.
h. Verify that the hose is flexible.
i. Proof test, in accordance with 4.6.3.4, after completing this test.
15
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business