Machinery Lubrication magazine published by Noria Corporation
Issue link: http://www.e-digitaleditions.com/i/520842
Advice for Greasing Electric Motors When using an audible or ultrasonic grease gun attachment for lubricating motors, be sure that the motor grease fi tting tube and grease gun coupler dthis risk. Thread sealant will fi ll the air gaps, lubricate the threads and seal out the water. 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. D Base number is an important parameter to monitor, especially for engine oils. Engine oil is alkaline (basic) because it is fortified with detergent additives to control deposits and neutral- ized acids generated during combustion. As the oil ages, these types of additives are used up, leading to a decrease in the base number. 2. C A single-point grease lubricator is used to pump grease to a limited number of grease points (normally one). It should be inspected regularly to ensure it is functioning properly. These types of lubricators are very useful for hard-to-reach lube points, enhancing safety and reliability. The pressure produced by single-point lubricators is much less than centralized greasing systems, so the correct answer is "C." 3. D Vacuum dehydration is a good option because it removes dissolved, emulsified and free water. Most of the other techniques are not capable of removing all forms of water, especially dissolved water. 1. A downward base number trend indicates: A) The type of base stock used in the fi nished oil B) The build-up of alkalinity in the used oil C) The neutralization of the acids in turbine oils D) The depletion of the alkaline detergent additive in engine oils E) The base oil density 2. Single-point grease lubricators: A) Are able to pump grease to a large number of grease points B) Are a reliable "set it and forget it" grease-dispensing system C) Are useful for hard-to-reach lube points D) Are capable of producing pressures similar to centralized systems E) All of the above 3. Vacuum dehydration is a good option for drying oil because: A) The method also vacuums up small particles B) The method maintains a vacuum that prevents buildup of moisture in the future C) The method boils the water off at high temperatures D) The method removes all three forms of water E) All of the above s m