Mechanical Maintance Flashcards
List the methods used to prevent chemical corrosion
- protective coating
- modifying the environment
- galvanising
- good design
- choice of materials used
- cathodic protection
- reporting serious deterioration
List the factors that accelerate chemical corrosion on unprotected metals
- moisture
- atmosphere pollution
- heat
what is pipe work impingement?
the accelerated erosion or corrosion arsing from continual removal of the protective oxide flims inside the pipe work by turbulent water.
How can impingement be recognised?
- By the appearance of variable depth of pits of accelerated water flow
- This usually creates Horse shoe shaped pits pointing upstream
Why do we use bearing extractors?
- To remove the bearing under control without undue force
-Without using a hammer
How do we use bearing extractors?
Bearing puller apply the necessary force in the correct areas using a fine threaded bar and arms to create a centralised lull so as not to damaged the shaft or housing
Describe items of equipment used yo measure bearing wear and their uses?
-Poker gauge- measure wear in the stern tube A brackets eliminating the need to disassemble
- Bearing wear down micrometer- used on thrust block bearings in a similar way to poker gauge
- plastiguage- used to meaure clearances in journal bearings and fitted and alignment on main gear boxes
- Micrometer - used to measure clearances or thickness over the whole surface of the journal bearing
List the parts of the keelaring coupling
- body
- o-rings
- washers
-collets - retaining nuts
Explain the purpose of using gaskets and gasket materials
- to fill the space between 2 mating faces to prevent the egress or ingress of forgiven matter
-to seal poor tolerance surfaces or slightly defective faces
Explain the principles of operation for a heat exchanger?
- devices which allow great from a fluid in one system to pass to another systems fluid
- without the 2 fluids coming into contact and mixing together
When using the 22 step maintenance process, list the principles to be considered before carrying out a maintenance activity
- obtain permission
-obtain relevant BR/UMS/manufactures documentation
-obtain correct tools
-order obtain stores - report defects in tools/spares/manpower
-move all gear to job location
-health and safety cost assessment - do you require a specific risk assessment?
- Verify the reported fault- dose it exist on the correct location
- check safety of immediate and adjacent work area for potential problems
- apply LOTO
List 6 areas where impingement is likely to be found inside pipe work
- badly matting flanges
- badly fitted joint material
- change in water flow
- change in pipe direction
- badly fitted valves
- excessively long pipes
List any 6 types of valves
- non-return
- globe valves
- sea clock
- cock
- ball valve
- butterfly valve
list 4 advantages of using heli-coils
- keep the original bolt thread size
- material is stronger that original thread
- material is relatively corrosion free
-quick and easy to repair stripped thread
list 5 methods of measuring bearing wear
poker gauge
micrometer
plastigauge
bridge gauge
bearing wear down micrometer
