MIL-DTL-25427B
TABLE IX. Impulse requirements for all pressure classes.
Sequence
Test description
Class 1000
Class 3000
Class 5000
1
Operating pressure
1000
3000
5000
Peak pressure
145% of operating pressure
1500
4500
7500
2
+ 5%
3
Temperature
25% at 275 °F and 75% at 225 °F
4
Cycle rate (cpm)
30 + 5
70 + 10
Rate of
min
10,000
45,000
75,000
pressure
5
rise
max
100,000
300,000
200,000
(psi/sec)
6
Number of cycles
100,000
200,000
200,000
4.8.14.1.2 Resonance dwell. The coupling shall be vibrated along each axis at the four
most severe resonant frequencies based on the results of the resonant search. Dwell time shall
be thirty (30) minutes at each test condition. The source dwells may be performed
simultaneously. If a change in the resonant frequency occurs during the test, its time of
occurrence shall be recorded and immediately the frequency shall be adjusted to maintain the
least resonance condition. The final resonant frequency shall be recorded.
4.8.14.1.3 Cycling. The couplings shall be vibrated along each axis for three (3) hours.
The cycling time shall be 3 hours minus the total resonance dwell time. The frequency shall be
swept over the range 15 Hz to 2000 Hz logarithmically. Sweep time for the 15 Hz to 2000 Hz
cycle shall be twenty (20) minutes.
4.8.14.2 Test item inspection for all pressure classes. During the sinusoidal and random
vibration tests, the test items shall be continuously monitored for sign of leakage and inadvertent
uncoupling. Following the vibration test, the coupling assembly and disconnected coupling
halves shall be examined for sign of excessive wear or damage. The test coupling shall be
subjected to the manual operation test specified in 4.8.2, leakage test specified in 4.8.5 and the
pressure drop test specified in 4.8.6.
4.8.15 Shock. The coupling shall withstand the following shock tests conforming to
MIL-STD-810, Method 516 and shall meet the requirements specified in 3.7.15.
4.8.15.1 Transit drop test. The ground support coupling half shall be connected to a
static pressure of 60 psi and shall be subjected to 26 drops from a height of 10 feet (average
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