Mech Sys Ops Flashcards
What is the desired temp a calorifier is maintained at?
66 Degrees C
How is the adjustment carried out on a Hot Water Calorifier?
Bimetallic strip, using appropriate tools
What state the following of a boost pump in a RO plant:
- location
- function
-operating parameters
supply water to HP pump
1 bar
before pre-filters
What state the following of a HP pump in a RO plant:
- location
- function
-operating parameters
increases pressure to
What are the uses of demon water?
- gas turbine wash
- helicopter engine wash
- medical use
- WE cooling systems
- Chilled water systems
- Diesel coolant systems
what are the uses of fresh water?
- drinking water
- upper decks wash down
- laundry
- bathroom/heads
- galley
- gas turbine wash
- fuel sep
- mess decks
- weapon mag space
- technical water RO plant
what is the purpose of a conductivity meter?
to give a visual indication of the presence of salt in the sea, potable and technical water of a certain engine room
describe how a conductivity meter works
- 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
what three factors determine the current flow between the electrodes?
- distance between the electrodes
- the amount of salt in the water
- the temperature of the water
how do you clean the electrode probes?
- isolate
- disconnect probe
- scrub nylon brush, 50;50 solution
- rinse and refit
What is the standard of quality of water in the RN?
fresh water - 250-300 ppm
demon water- 2.5-25ppm
what is meant by super chlorination?
the process of sterilisation of FW systems using extremely high dose of chlorine
when is super chlorination done?
- on commissioning
- after the cleaning or re-coating internal surface of fresh water tank
- when is it considered necessary
what formula is used to determine amount of chlorine used for super chlorintion?
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
list the steps taken to minimise contamination and stagnation in fresh water systems on board
- swapping tanks every 24 hours
- aerator
- chlorine
- non-return valves
- lockable sounding tube caps
- leak off lines
- air escape tubes
- no dead legs
what is looked for when inspecting plumbing?
- physical damage
- vibration damage
- noise shorts
give a brief description of osmosis
natural process where a solution of low concentrate flows through a semi-permeable membrane to dilute of high concentration. this will continue till equilibrium
give a brief description of reverse osmosis
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.
state hazards and safety precautions of an RO Plant
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
main courses of damage to PALL DT modules
- incorrect torque setting
- pressure on permeate discharge line
- vaccum
the definition of a mount
to minimise radiated and self noise to improve habitlility and reduce damage to equipment.
what are the reasons for mounting?
- 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
what are the different types of mounts?
x mount
j mount
PD mount
L mount
M mount
what is the application of a PD Mount?
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
