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Shock test acceptance criteria shall be as follows |
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| MIL-P-17639F(SH)
4.6.7 .2.1 Before and after shock test, the pump and driver and other
components susceptible to internal derangement shall be disassembled to the
extent necessary and the critical dimensions and running clearances measured,
calculated, and recorded. During this disassembly, the critical components
and assemblies subject to shock damage and derangement shall be identified and
listed in the inspection record and after completion of the test. The condition
of each component and assembly shall be determined and recorded. Shafts,
impellers, and turbine rotors, motor rotors, and reduction gears shall be
inspected by one of the applicable non-destructive test procedures, other than
radiography, specified in MIL-STD-271.
4.6.7.2.2 Before and after the shock test, tests in accordance with 4.6.3
shall be performed to determine the changes in performance characteristics of
the pump. Vibration measurements shall be taken at the bearing caps or housings
of the pump and driver at equal speeds during the initial and final capacity
test to determine the changes in mechanical operation.
4.6.7.2.3 The unit shall be mounted on the shock machine or barge essenti-
ally identical to the actual shipboard installation. The contracting activity
will furnish the contractor a drawing of the shipboard mounting arrangement and
foundation's stiffness. Horizontal pumps, when tested in the inclined position
on the medium weight shock machine, shall be oriented so that the direction of
shock is perpendicular to the axis of the pump rotation. The pump shall be in
operation during the first, third, and fifth blows of the shock test on the
floating barge. Variable speed pumps shall be operated at the minimum speed and
pressure required to insure lubrication of bearings and wearing parts. Other
pumps shall be operated at the lowest rated speed.
4.6.7.2.4 The pump shall be carefully observed during each shock blow and
thoroughly examined visually after each blow. After each blow, the unit shall
be operated at as close to maximum rated speed as possible and checked for
abnormal noises and vibrations and proper functioning of controls. Turbine
driven pumps may be air driven. Tightening of bolts during shock tests will not
be permitted. If any bolt loosens during the test, the equipment manufacturer
shall provide a corrective procedure which must be approved by the design review
agency.
4.6.7 .2.5 Shock test acceptance criteria shall be as follows:
(a) There shall be no breakage of parts, including mounting bolts.
(b) There shall be no distortion or derangement of any part which
would render the unit incapable of performing as specified.
(c) The amplitude of vibration after test at maximum rated speed
shall be less than twice the amplitude measured at the same
speed before the test.
(d) Adequate lubrication to all bearings shall be maintained.
(e) Critical dimensions and running clearances have been maintained.
(f) There shall be no significant change in the head-capacity curve.
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