MIL-DTL-20176G
4.6.3 Tube and cover thicknesses. A 4-foot (1 219 mm) length of hose identical to the hose
submitted for the lot, except that it shall be without helix wire, shall be submitted. Hose shall be
inspected for measurements of the tube and cover thicknesses and the tests for the properties of
the rubber components (see 4.6.10 through 4.6.10.7 and 4.6.11). The thicknesses of the tube
and cover shall be measured on specimens removed from each end of the hose section to
determine conformance to 3.4. The thicknesses shall be determined by the procedure given in
ASTM D 380, except that only buffed specimens shall be measured. The respective values found
for the tube thickness shall not be averaged, but shall be regarded as independent measurements,
each of which should meet the requirement. The respective values for the cover thicknesses shall
be treated in the same manner.
4.6.4 Unit weight. The unit weight of hose samples selected shall be determined by weighing the
hoses without couplings. The reading shall be accurate to the closest lb (kg). The weight of each
hose shall be divided by its length to determine conformance to 3.4. The entire lot shall be
rejected if any sample hose fails to meet the requirement for unit weight.
4.6.5 Hydrostatic proof pressure. Each hose assembly in the lot shall be subjected to the proof
pressures specified in table III, in accordance with ASTM D 380. The proof pressure shall be
held for 5 minutes and the hose and fittings examined for leakage or other indication of weakness.
Nonconformance to 3.6.6 shall constitute failure of this test.
4.6.6 Dimensional stability. The effect of the proof test pressure on the length, od, and twist of
all sample hoses using water as the test fluid shall be determined as specified in 4.6.5 and
ASTM D 380. Before starting the test, a 10 psig (69 kPa (gage)) hydrostatic pressure shall be
established in the hose, and the length, od, and zero index for twist shall be measured
(see ASTM D 380). At the end of the 5-minute period of 4.6.5 and while the pressure is
maintained, the length, od, and twist of the hose shall be measured for the determination of
dimensional stability while the hose is under proof pressure. The pressure shall then be reduced to
zero psig and the hose left in this condition for 5 minutes. At the end of this period, the diameter
and length of the hose shall be measured. Nonconformance to 3.6.1 shall constitute failure of this
test.
4.6.7 Burst pressure. One hose section not less than 32 inches (813 mm) in length, shall be
submitted for the burst pressure test. The burst pressure of this section in the straight condition
shall then be determined in accordance with ASTM D 380. Nonconformance to 3.6.7 shall
constitute failure of this test.
4.6.8 Tensile pull load. One hose section not less than 12 inches (305 mm) in length, shall be
submitted for the tensile pull test. The section of hose shall be equipped with couplings and
clamps (see 3.7.1 and 3.7.3). The assembly shall be subjected to the tensile pull loads specified in
table III for the appropriate size for a period of not less than 5 minutes without damage or
slippage of couplings. Nonconformance to 3.6.2 shall constitute failure of this test.
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