MIL-P-5238C
4.5.3 Break-in-run. The pump shall be run dry for a period of 3 to 5 minutes.
During this time the pump shall be rotated such that the pump shaft is slowly
rotated in a vertical plane through 180°. Any sounds indicating rubbing,
binding, or excessive looseness shall be a cause for rejection. A wet run
in fluid shall be conducted in accordance with the detail specification
requirements.
4.5.4 Leakage
4.5.4.1 outlet. Apply fuel pressure to the pump outlet varying from 4 inches
of fuel head up to 120 psig at seven different pressure levels for 5 minutes
duration each. There shall be no permanent distortion, failure, or external
leakage. Internal leakage across the check valve(s) shall not exceed the
allowable. The individual test shall be conducted at the minimum and maximum
pressure levels only for 2 minutes duration each.
4.5.4.2 External. There shall be no external leakage at any time except as
allowed through the drive shaft seal (3.6.4). For individual tests, fluid
pressure shall be applied to all internal fluid carrying cavities from 4 inches
of fuel head up to the maximum pump pressure at three pressure levels for a
duration of 5 minutes each. There shall be no external leakage except as allowed
by the detail specification from drain ports.
4.5.4.3 Plug-in units. Plug-in pump assemblies shall be tested to demonstrate
that the fuel loss occurring during removal and installation is in accordance
with the detail specification allowances. This test may not be required for
individual inspections except in accordance with the acceptance test plan.
4.5.5 Calibration. For the First Article inspection, a standard calibration
shall consist of recording input power and output pressure for at least seven
output flows from zero up to the maximum flow capacity at ground level and at
three different altitude levels, in accordance with the detail specification.
For individual inspections, the calibration may be conducted at ground level
only and for four output flows. All ground level calibration runs shall be
Altitude calibra-
conducted with the fuel temperature between 60°F and
tions shall be conducted in two series, one with the fuel temperature at the
maximum of 3.2.4, and another with the fuel temperature no higher than O°F.
4.5.6 Blocked inlet screen. With 50 percent of the inlet screen(s) blocked,
altitude calibrations shall be accomplished with low and high temperature fuel.
4.5.7 Pump down. With the pump operating in the test stand, the fuel flow
controls shall be adjusted to cause the fuel head above the pump to drop at
a rate of 1 inch per minute while maintaining rated flow and pressure. The
fuel head and output flow and pressure shall 1 be recorded at intervals no
greater than l-inch change of head. Fuel returning to the tank shall not
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