Theory 4 Flashcards
Conduction is
Heat transfer through direct contact
Convection
Heat transfer through mass motion of molecules
Radiation transfer is
Heat transfer through electromagnetic radiation
Cool room and cold room are
Cool-fridge
Cold-freezer
The lower the pressure does what to the boiling point
Lowers it
Increase the pressure it will what to to the boiling point
Increase it
Sensible heat is
Temperature change but no change in state
Latent heat is
Change in state but no increase in temperature
If a temp goes from 120 to 90 what is the sub cooling
30 sub cooling
Cold room temp
-18 -22
Fruit and veg temp
+4 +6
Galley ready use cupboard temp
+5 +7
Liquid receiver does what
Holds and retains refrigerant during maintenance and provides seal between condenser and tev
What does the liquid line stop valve do
By shutting this and running compressor it will cause liquid receiver to fill
What is the Montreal protocol
Agreement to cut out CFC production
Ozone depletion substances
CFCs,HCFCs,HALONs
Kyoto summit
Agreement to reduce greenhouse gases
5 leak detections
-IRLDs
-oil slicks
-spectolyne dye
-snoop
-halogen leak detector
3 oils in rn oil refrigerant
Om70-general purpose
Suniso-type 23
Sw68-used with R134a refrigerant
Hygroscopic
Absorbs moisture rapidly
Tin sizes
500ml to 5ltr
How to add oil to sump
Sump filler plug
Hand pump
Dosing pot
Chilled water plants cool
Weapons systems
Radars
Ships computer systems
ATUs
Exhaust fans are at what level and remove what
At deck level and remove any remaining refrigerant
8 steps when entering freezer
-Someone knows where u are
-BA charging
-fans running
-no smoking
-IRDLs is working
-warning lights work
-century with u
-door safety works
Fan supply/fan exhaust
WCs,galley,machinery space
Fan supply/natural exhaust
Stores room and workshop
Natural supply/fan exhaust
Remove flammable vapour
Natural supply/natural exhaust
Minor occupied areas
6 filters
Panel
Supply
Grease
Lint
Dust
Flameproof gauzes
Stps require how many changed per hour
15
Magazines need how much fresh air
100%
Recirculated air percentages
67% re circulation
33% drawn in
Mk 6
Mk7
Mk 3
200 ft3
200ft3
500ft3
How to citadel test
Close all openings
Open AFU inlets and start AFU
restrict access-air locks used
Search for leaks
Record result of test
Air bleed valves set at
Half inch
Crash stop is
Stops vents round ship in event of fire and is in scc/hq1
4 things hydraulics are used for
Weapons systems
Water tight doors
Deck machinery
Steering
Fluid is
Substance that takes the shape of its container
Difference between liquid and gas
Liquid used in hydraulic and can’t be compressed
Gas used pneumatic
5 reasons hydraulics are good
Reliable
Simple to understand
Infinite range of speed
Easily reversed
Withstand overload
No spark risk
Why are hydraulics bad
Fire risk with mineral oil
Noise
Risk of contamination
Less efficient-85-95%
Denso tape
Used on upper deck
Prevent corrosion
Stored in inflame stores
O-seals melt at
300
PPE with flurocarbon
Boots
Gloves
Overalls
Visor
Petroleum based fluid is
Inexpensive and general purpose
Synthetic based fluid is
Man made
Specific purpose
Ox30 is what colour and used when
Red and used on submarines
Om33 is what colour and used on
Yellow and carriers
Ox40 is what colour and used on
Green and used on type 45
Hazards with hydraulics
Skin irritation
Change clothing
Leaks cleaned up immediately
Flexi hoses in date
-Always consult the hazard data sheet
Hydraulic fluid must be
Incompressible
Good lubricant
Good sealing properties
Gives up heat
Oil additives
Anti foam
Anti oxidants
Anti corrosion
Demulsizillity
Pour point depressant
Where does hydraulic oil contaminants come from
Airborne
Construction dirt
Dirt in new fluid
-Dirt produced by wear in new system
-dirt from human source
How to reduce contamination
Good design
Filter maintenance
Clogging indicator
Good working practices
Caps on open ended pipes
Clean working area
2 hydraulic systems
Ringmain
Stand alone power packs
2 types of pumps
Dynamic and positive
5 types of positive pumps
External gear pump
Internal gear pump
Vane pump
Single piston pump
Lobe pump
What does an actuator do
Converts energy into mechanical motion
What does a drain leg do
Used for cooling and to return back to the tank
What does an accumulator do
Store’s potential energy and smooths out pulsations
Axial pumps are used in (bi-directional)
Stabiliser system
CPP
Steering system
2 characteristics of axial pumps
Variable capacity
Bi-direction
2 types of actuators
Linear
Rotary
What does a swash plate do
Can adjust the pressure by changing angle and applies pressure to piston pumps
What percentage of sw is ejected
80%
What’s the tds after desalination
Between 250-300ppm
After the salt water is mixed what’s the ppm
56000ppm
What’s the microns at stage 1 of the filter bag
60
What’s the microns after the pre filters
10 microns
What bar is displacement pump
10-65
What’s does the concentration control valve do
Closed down increases back pressure to ensure reverse osmosis happens
Chlorine levels kept at what ppm and supervised by who
0.2ppm
Section head
Purpose of fresh water systems
Laundry
Galley
Showers/sink
Water heaters
Medical use
Bridge window washers
Fresh water hose reels
Machinery cooling
Gas turbine washing
Bringing on fresh water steps 1-7
-Draw hoses
-Unscrew deck cap to filling connection
-fit gooseneck to relief valve
-connect hoses to shore water supply
-open shore filling supply valve and flush through the hoses
-Carry out water tests(visual,chlorine,taste)
-shut off shore filling supply valve
What size are the tins
500ml and 5L
How may oil be added to the sump
Sump filler plug
Hand pump
Dosing pot
Chilled water plants replaces
Replace the evaporator with chiller with ring main
Chilled water plants cool what
Weapons systems
Radars
Ship’s computers
ATUs
What 2 things control the calorifier
Thermostat and pressure gauge
What does a run down valve do
Drains calorifier for maintenance
Air eliminator does what
Reduce affects of water hammer
What additives are in the synthetic oil
Anti-foam-prevents bubbles
Anti oxidants-reduce sludge
Anti-corrosion
Denulsibility-separates water
Pour point depressant-maintains the oil to pour
How to reduce contamination
filter maintanence
Clogging indicator
Good working practices
Guardian filter pack
caps on open ended pipes
clean working area
2 types of actuators
Linear,rotary
Chlorine levels are kept at what ppm
0.2ppm
How many air changes does an stp require
15 per hour
Pre particulate filter does what
Paper filter to remove particles
Particulate filter does what
Made of gas and removes bacteria
Gas filter does what
Removes warfare chemicals
When to do citadel test
Annually
Prior to ded
During hats and says
All ships during FOST work up
Crash stop button does what
Built in ventilation stop system built in hq1/scc
What makes a fluid good
-Substance that can take the shape of its container
-capable of transmitting power
-it can be a liquid or gas
Difference between pneumatic and hydraulic
Pneumatic-air system
Hydraulic-liquid system
Bi directional flow is in what
Stabiliser system
Cpp system
Steering system
Drain leg is
Used for cooling and to return to the tank
TDS stands for
Total dissolved solids
TDS of sea water is at around
34000
Chlorine levels are kept at what and who supervises it
0.2ppm and section head
What ppm goes to the made water tank
350
Permeate and made water are made through what filter
Membrane
How to control calorifier
Thermostat
Pressure gauge
Pressure relief valve
A run down valve does what
Allows you to drain calorifier for maintenance
3 filters
Pre particulate-paper,coarse particle
Particulate-glass,bacteria,holds onto it
Gas filter-warfare chemicals,charcoal
