FED-STD-791 Lubricants, Liquid Fuels, And Related Products, Testing Method OfThis test method standard is composed of standard test methods for sampling, inspecting and testing lubricants, liquid fuels and related products. It is issued pursuant to the Federal Property and Administration Services Act of 1949, as amended and its application to the purchase of commodities referred to herein is mandatory on all Federal agencies.

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'�NOTE:This draft dated 15 April 2006' by DasH - Page 344 of 460

FED-STD-791D

Start drive motor.

Increase gear speed by turning the rpm adjust control clockwise until the

specified 10,000  100 rpm is obtained. Measure speed with the electronic

rpm counter.

Turn load bypass control to "CLOSE" position.

Apply load slowly by turning the load adjust control clockwise. Stop when

the load oil pressure is 34 kPa gage (5 psig).

NOTE 3:

In adjusting load oil pressure, take care not to overshoot the desired

pressure.

Check gear speed.

Turn timer switch to "START" position. The 10-minute test run now begins.

10.

Record all pertinent data about midway into the 10-minute test run.

11.

At the end of the l0-minute run, the electric timer will automatically stop the

drive motor and open the load bypass valve. However, the timer switch on

the control console will remain in "START" position, the load bypass control

will remain in "CLOSE" position, and the rpm adjust control will remain in

running position. To restore these to their respective off positions:

a. Turn load bypass control to "OPEN" position.

b. Turn timer switch to "STOP" position.

c. Turn rpm adjust control to "ZERO" position.

12.

Make visual scuff inspection of the narrow test gear, as follows:

a. Turn 3-way valve M to bypass flow around the Ryder gear machine.

b. Remove corks from inspection holes on the gear case.

c. Blow off excess oil from the test gear with compressed air through the

inspection hole.

d. Install microscope and inspection light.

e. Focus microscope and adjust the 20% grid lines over the contact area of the

tooth. (See Figure 10).

f. Set indexing ratchet wheel to "No. 1" position.

g. Estimate the percent scuff on No. l tooth to the nearest 5%, and record the

value (See Figure 12).

h. Operate indexing ratchet to give No. 2 tooth, then No. 3 tooth, etc., repeating

step (g) until all 28 teeth have been examined

i. Remove microscope and light. Replace corks in the holes.

j. Turn 3-way valve M to running position.

k. Lock indexing ratchet in disengaged position.

13.

Repeat steps (3) through (12) at the next test load of l70 kPa (10 psig) load

oil pressure.

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