THIS MONTH, MACHINERY LUBRICATION CONTINUES
ITS "TEST YOUR KNOWLEDGE" SECTION in which we
focus on a group of questions from Noria's Practice Exam for
Level I Machine Lubrication Technician and Machine Lubricant
Analyst. The answers are located at the bottom of this page. The
complete 126-question practice test with expanded answers is
available at store.noria.com.
TEST YOUR KNOWLEDGE
Answers
1. C
Sulfur-phosphorus extreme pressure (EP) additive systems are chemically
aggressive and work at high temperatures generated from high loading. Under high
loads and associated high temperatures, sulfur-phosphorus EP additives form an
adherent surface film that transforms to a ductile, metal soap sacrificial film to
help protect gear components from wear.
2. D
Because of the non-woven media structure, depth filters generally have inconsistent
pore sizes and high dirt-holding capacity. Thus, the correct answer is D.
3. D
Both simple and complex soaps consist of long-chain fatty acids and metal
hydroxide. The main difference between simple and complex soaps is the presence
of short-chain fatty acids in complex soaps. This improves the thermal stability
of the thickener and leads to higher dropping points and thus higher operating
temperatures. The dropping point of a grease is the temperature at which it passes
from a semi-solid to a liquid state under specific test conditions.
1. The lubricant formulation most commonly used for
industrial, heavily loaded gear systems is:
A) R&O gear oil
B) Zinc-phosphorus anti-wear (AW)
C) Sulfur-phosphorus extreme pressure (EP)
D) 000 EP grease
E) Compounded gear oils
2. Depth filters:
A) Involve a torturous path between fibers with high dirt-holding capacity
B) Are made using square-weave wire cloth
C) Have pores of inconsistent sizes
D) Answers A and C
E) All of the above
3. What is the prime advantage to newer "complex" soap
thickeners vs. older simple soap thickeners?
A) Higher cost
B) More appealing color
C) Harder grease
D) Higher dropping point and thus higher operating temperature
E) Better low-temperature pumping
