Lubrication Systems & Maintenance Flashcards
7 cards from real CLS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Lubrication Systems & Maintenance flashcards as text
A technician notices a white, milky appearance in the sight glass of a gearbox. What does this MOST likely indicate?
Answer: Water contamination emulsified in the oil
A milky or white appearance indicates water has emulsified with the oil, forming a water-oil emulsion that severely reduces lubricating film strength.
Which lubrication system maintenance task is MOST critical to perform before commissioning a newly installed centralized system?
Answer: Flushing lines to remove machining chips, moisture, and contamination
Pre-commission flushing removes construction debris, chips, and moisture from new lines, preventing these contaminants from entering bearings and causing immediate damage.
What role does a pressure relief valve play in a centralized grease lubrication system?
Answer: It protects the pump and lines from over-pressurization during blockages
A pressure relief valve opens at a set pressure to bypass lubricant back to the reservoir, protecting the pump, lines, and fittings from damage if an outlet becomes blocked.
In a circulating oil system, what is the typical recommended minimum reservoir retention time for the oil?
Answer: 3 to 5 minutes
A minimum retention time of 3–5 minutes allows entrained air to escape, heat to dissipate, and particles to settle before oil re-enters the system.
What maintenance activity is indicated when a progressive divider valve cycle indicator pin remains extended continuously?
Answer: A downstream outlet is blocked, preventing the valve from completing its cycle
A permanently extended cycle indicator pin on a progressive valve means the divider block cannot complete its cycle, almost always because a downstream line or bearing is blocked.
Which standard is commonly referenced in the US for establishing oil cleanliness targets in industrial lubrication systems?
Answer: ISO 4406 cleanliness code
ISO 4406 provides a three-number particle count code (4/6/14 µm channels) used universally to define and target oil cleanliness levels in industrial systems.
When establishing a preventive lubrication maintenance schedule for a facility, what is the BEST primary data source for setting relubrication frequencies?
Answer: Equipment OEM recommendations adjusted for actual operating conditions
OEM recommendations provide the baseline engineering data, which should then be adjusted for site-specific factors like temperature, contamination, load, and speed to create an accurate schedule.