MIL-S-8959(ASG)
4.5.4 Seal compatability.- 0The sample specimen prepared as specified in
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4.3.1.2 shall be maintained at 160 ± 10° F for 6 days prior to performing the test
specified in 4.5.5 for the applicable .ClaSs. After completion of the endurance . ...*
. tests,
...
all packings and the metals in contact with the packings shall be examined for Sticky
or gummy residue and discoloration or corrosion of the metals.
4.5.5 Endurance cyc l" ng.- The same assembly and packings used in 4.5.4 shall be
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used for this test. Prior to testing, the unit shall be serviced to the precharge
pressure with the proper fluid. The-assembly shall be installed in a test stand-cap-
able of alternately loading and unloading it. The assembly shall be subjected to
cyclic operation which simulates the loading and duplicates the swiveling and bending
loads, if any, which would occur in service. All tests shall be conducted at room
temperature.
The procedure for class 1
4.5.5.1 Procedure for class hydraulic springs.-
hydraulic springs shall be:
{a) Cycle the unit 1,000 full design strokes from zero
load to 100 percent applied load.
(b) Unless otherwise specified by the procuring activity,
maintain the unit at installed load for a 24-hour
period after the cycling test.
The procedure for class 2
4.5.5.2 Procedure for class 2 hydraulic springs.-
hydraulic springs shall be:
(a) Cycle the unit 1,000 full design strokes from zero
load to 100 percent applied load.
(b) Cycle the unit 10,000 times, ±25 percent of fu11
stroke, about its normal installed position.
The maximum compressed stroke shall not exceed
95 percent of the full stroke.
(c) Cycle the unit 50,000 times, ±12.5 percent of full
stroke, about its normal installed position. The
maximum compressed stroke shall not exceed 95 per-
cent of the full stroke.
(d) Maintain the unit at the installed load specified by
the procuring activity for four 24-hour periods.
The periods shall be after the 10,000 cycles of
4.5.5.2(b) and at approximately equal intervals
during and after the 50,000 cycles of 4.5.5.2(c).
There shall be no external leakage during each of
these 24-hour periods.
The cycling tests of 4.5.5.5.2(a), (b), and (c) may conducted in any convenient order.
4.5.5.3 After completion of the cycling tests for the applicable class of
hydraulic spring, a load-stroke test shall be conducted. At 90 percent of full stroke,
the supporting load shall be within 10 percent of the design requirements,
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