Mech Sys Ops Flashcards

1
Q

What is the desired temp a calorifier is maintained at?

A

66 Degrees C

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2
Q

How is the adjustment carried out on a Hot Water Calorifier?

A

Bimetallic strip, using appropriate tools

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3
Q

What state the following of a boost pump in a RO plant:
- location
- function
-operating parameters

A

supply water to HP pump
1 bar
before pre-filters

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4
Q

What state the following of a HP pump in a RO plant:
- location
- function
-operating parameters

A

increases pressure to

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5
Q

What are the uses of demon water?

A
  • gas turbine wash
  • helicopter engine wash
  • medical use
  • WE cooling systems
  • Chilled water systems
  • Diesel coolant systems
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6
Q

what are the uses of fresh water?

A
  • drinking water
  • upper decks wash down
  • laundry
  • bathroom/heads
  • galley
  • gas turbine wash
  • fuel sep
  • mess decks
  • weapon mag space
  • technical water RO plant
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7
Q

what is the purpose of a conductivity meter?

A

to give a visual indication of the presence of salt in the sea, potable and technical water of a certain engine room

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8
Q

describe how a conductivity meter works

A
  • two electrodes are placed at a predetermined distance apart in feed water system
  • current is applied in series with a lamp
  • the fresh water being high resistance, allows only a min current to flow
  • the presents of salt in water reduces resistance, between the two, increasing the current
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9
Q

what three factors determine the current flow between the electrodes?

A
  • distance between the electrodes
  • the amount of salt in the water
  • the temperature of the water
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10
Q

how do you clean the electrode probes?

A
  • isolate
  • disconnect probe
  • scrub nylon brush, 50;50 solution
  • rinse and refit
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11
Q

What is the standard of quality of water in the RN?

A

fresh water - 250-300 ppm
demon water- 2.5-25ppm

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12
Q

what is meant by super chlorination?

A

the process of sterilisation of FW systems using extremely high dose of chlorine

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13
Q

when is super chlorination done?

A
  • on commissioning
  • after the cleaning or re-coating internal surface of fresh water tank
    • when is it considered necessary
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14
Q

what formula is used to determine amount of chlorine used for super chlorintion?

A

D= c/1000 x 100/A x V

D= chlorine
C= initial require amount of chlorine
A= % of chlorine in compound
V= volume of water

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15
Q

list the steps taken to minimise contamination and stagnation in fresh water systems on board

A
  • swapping tanks every 24 hours
  • aerator
  • chlorine
  • non-return valves
  • lockable sounding tube caps
  • leak off lines
  • air escape tubes
  • no dead legs
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16
Q

what is looked for when inspecting plumbing?

A
  • physical damage
  • vibration damage
  • noise shorts
17
Q

give a brief description of osmosis

A

natural process where a solution of low concentrate flows through a semi-permeable membrane to dilute of high concentration. this will continue till equilibrium

18
Q

give a brief description of reverse osmosis

A

reverse of osmosis, by adding sufficient pressure to the salt solution to over come osmotic pressure head.
level of pure water will increase leaving the salt solution a high concentrate.
process removes, 90-99% of TDS and bacteria.
must be chlorinated before it is fit for human consumption.

19
Q

state hazards and safety precautions of an RO Plant

A

High Voltage Electrical hazard
- 440v
- ensure supplies to both pump motor and control system are isolated
- tag out carried out

High Pressure Hazard
- do not work on pressurised systems
- security of fixtures and fittings
- check for correct operation

Chemical Hazard
- correct PPE
- avoid spillages and skin contact
- haz data sheets available

20
Q

main courses of damage to PALL DT modules

A
  • incorrect torque setting
  • pressure on permeate discharge line
  • vaccum
21
Q

the definition of a mount

A

to minimise radiated and self noise to improve habitlility and reduce damage to equipment.

22
Q

what are the reasons for mounting?

A
  • provide vibration isolation between equipment and the ships structure
  • reduces levels of vibrations transmitted through to the ships structure to minimise self noise
    -controlled flexibility
23
Q

what are the different types of mounts?

A

x mount
j mount
PD mount
L mount
M mount

24
Q

what is the application of a PD Mount?

A

PD mount is a general purpose resilient mount for heavy equipment. it is not fully captive design and thus be fitted with accelerators and decelerators

25
Q
A