Industrial seal self study guide - SKF.com

Chapter 7 Review (cont.)
6. Spiral grooves (machine lead) may promote seal leakage.
❑ True ❑ False
7. Tumbled stone finishing provides a positive solution to machine lead.
❑ True ❑ False
8. Shaft speeds should be reduced when shaft finish or eccentricity (run-out) is reduced.
❑ True ❑ False
8. F
9. Revolutions per minute (rpm) is a better seal selection guide than the surface speed
at the contact point between the seal and shaft (fpm: feet per minute).
❑ True ❑ False
9. F
10. The shaft surface should be smooth enough to prevent excessive seal wear, but
“rough” enough to form lubrication holding pockets.
❑ True ❑ False
10. T
11. Ferrous and other commonly used metallic materials (such as aluminum) are
acceptable bore materials.
❑ True ❑ False
6. T
7. F
11. T
12. Roto preening is recommended to dress the shaft and remove lead introduced during
the machining operation.
❑ True ❑ False
12. F
13. Imperfections such as surface burrs, nicks or rough spots on the shaft surface can
damage the lip as it slides on the shaft.
❑ True ❑ False
13. T
14. Bore material must be metallurgically compatible with the seal type that is used.
❑ True ❑ False
15. Bore-tite on a metal clad seal’s O.D. efficiently fills major bore imperfections.
❑ True ❑ False
16. It is acceptable to use inch sized seals in metric sized equipment.
❑ True ❑ False
14. T
15. F
16. F
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