MIL-DTL-70526B (AR)
4.4.5 Porosity test. This test shall be performed 100%
until 1500 consecutive units have passed without failure. After
the above criteria has been met, sampling shall be performed
randomly at the rate of 18 delay assemblies for each production
shift or portion thereof. If any one of the 18 delay assemblies
fail to meet the requirements of 3.6, the total shift production
shall undergo the porosity test and an additional 1500 units
tested to quality sampling again. (See 6.13) Each delay assembly
shall be conditioned at 145 +/- 5 degrees F and assembled to the
porosity test equipment. Nitrogen gas under a pressure of 1000
PSIG plus or minus 50 PSIG shall be applied to the delay column
at the threaded end of the housing. The pressure at the exit end
of the delay column shall be recorded at 0.5 seconds, 80 seconds
and 110 seconds. The pressure reading at 0.5 seconds shall be
recorded and used as the zero reference.
4.4.6 Performance testing.
4.4.6.1 Pilot composition test. For first article and each
new lot of constituent ingredients, a pilot composition test
shall be performed on 150 delay assemblies utilizing both
ballistic and static spin testing. Five pilot batches are to be
produced at tungsten contents differing from sample to sample by
a constant difference. The difference shall not exceed one part
by weight. From each of the five completed batches of delay
composition, enough material shall be selected to load 30 delay
assemblies. If the sample is taken before the entire batch is
pelletized, the representative sample shall be selected in 30
approximately equal increments taken from different areas in the
mix, tumbling the mix often so as to minimize the chance of
misleading results from segregation. If the sample is taken from
a pelletized batch, a random sample of pellets shall be selected
for use in this test. All thirty delays from each batch shall be
loaded with igniter, delay composition, flash, and have the
washer installed. Fifteen of the delays shall then be selected
at random for static spin testing and the remaining delays shall
be loaded with the boron potassium nitrate and delay closure for
ballistic testing. All delays shall have the selector caps
installed. Selector caps used for spin testing may be reused
only for other spin test delays provided care is taken to assure
pyrotechnic material is removed from the cap and gasket prior to
reuse. All thirty delays from each lot shall be porosity tested
and radiographically inspected per 4.4.5 and 4.4.10 respectively
and must meet the requirements of 3.6 and 3.7 respectively.
Fifteen delay assemblies shall be statically spin tested in
accordance with 4.4.8, and the results tested for outliers per
6.12. If the spin test results for the batch exhibit no long
time outliers per 6.12, the remaining fifteen completely loaded
delay assemblies shall be ballistically tested in accordance
with 4.4.7. If the requirements of 3.8.1 are not met, or if the
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