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|  MIL-S-24603A(SH)
4.6.7 Jam test. With the comminutor operating at no-load, a single washer,
nut, or bolt of sufficient size and gauge shall be fed into the cutters to jam
(stall) the comminutor. This sequence shall be repeated 30 times. Results of
this test shall comply with the requirements of 3.3.5.
4.6.8 Maintainability test. The comminutor shall be jammed as in 4.6.7;
secure and tag power to the comminutor; drain comminutor. Manual removal of the
cutter assembly, unjamming cutters, and re-assembly and restoration of the unit
to operating condition shall not exceed 1 manhour as specified in 3.9.4.
4.6.9 Back-Pressure test. Simulated sewage slurry of 1 percent solids by
weight shall be gravity fed through the comminutor in sufficient quantity to
maintain full-pipe flow at the comminutor inlet without a down-stream flow
restrictor. Sewage may be simulated using a mixture of water, and dry dog food,
paper or other acceptable solid materials. The pressure drop across the
comminutor under the prescribed flow condition shall not exceed 1 foot of water.
4.6.10 Jam-failure repair. Starting with the power to the comminutor
secured and tagged and the unit drained, repair parts predicted and identified by
3.9.1 shall be replaced. Time to execute the simulated repair action shall not
exceed 2 manhours.
4.6.11 Vibration test. The comminutor and its associated motors, con-
trollers, and drive mechanisms shall be vibration tested under normal operating
conditions as specified in 3.7.5. When specified in the contract or order,
vibration testing reports shall be prepared (see 6.2.2).
4.6.12 Reliability-durability test. Test shall be run using sea water or a
simulated 3-1/2 percent salt-water solution formulated from commercially
available salt compounds for this express purpose. Salt water sewage shall be
simulated by adding 1 percent solids, by weight, to the salt solution (see
4.6.9). The duration of the test shall be at least 250 hours and conform to the
following:
(a) First test phase:
(1) Accumulates a minimum of 150 motor-controller on-off
cycle. Shut comminutor off only under zero flow condition.
(2) Accumulate at least 120 hours of run time on comminutor.
(3) At least 40 hours of the 120 hours of run time shall be
introduced to the comminutor intermittently at regular
internals to simulate a shipboard situation where sewage
will be seen in slugs. The comminutor shall be subjected to
a minimum of 200 of these wet flow cycles during the 40
hours.
(b) Second test phase:
(1) Secure comminutor and leave unit installed in the dry mode
for 60 hours, and the wet (submerged) mode for 60 hours.
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