The lowest concentration of the gas in air that will support a self-propagating flame when ignited.
LNG1032-244 :
A :
What is the lower flammable limit (LFL) of a combustible gas? Wrong or Missed Data? Click
30% LFL
LNG1032-247 :
A :
At what gas concentration should the alarm point be set for the gas detection units on board an LNG vessel? Wrong or Missed Data? Click
Detectors should be subject to regular calibration every 3 months to ensure that the zero and span of the instrument is correct.
LNG1032-248 :
A :
What are the requirements for testing of the gas detectors? Wrong or Missed Data? Click
Detectors should be subject to regular calibration every 3 months to ensure that the zero and span of the instrument is correct. On cyclic sampling systems, suction line integrity and filters should also be checked at regular intervals.
LNG1032-249 :
A :
What are the requirements for testing of cyclic sampling gas detection systems? Wrong or Missed Data? Click
At least 2 sets
LNG1032-250 :
A :
How many sets of portable gas detection equipment, suitable for detecting vapour up to the LFL of gas on board, must an LNG vessel carry?
Wrong or Missed Data? Click
Top, mid height and bottom of the tank.
LNG1032-251 :
A :
When testing a confined space for gas prior to entry, where should the sample be taken from? Wrong or Missed Data? Click
Infra-red type instrument
LNG1032-252 :
A :
What type of meter is used to measure hydrocarbon concentration in an inert atmosphere? Wrong or Missed Data? Click
Sample A.
LNG1032-253 :
A :
Which sample of air, having the dew point readings given, would contain the most moisture? Sample A with a dew point of -20°C or Sample B with a dew point of -45°C?
Wrong or Missed Data? Click
Evacuate the space immediately.
LNG1032-259 :
A :
If, while work is in progress in a confined space, either the O2 reading is seen to decrease or the gas content increase during a periodic check, what should be the first course of action?
Videotel CBT LNG Vers 1.0.32 (QUESTIONS & CORRECT ANSWERS)
3.Support Systems (Module 3) - test for Electrician
Main cargo and stripping pumps. HD compressor. Manifold valves. Cargo loading and discharge valves.
LNG1032-260 :
A :
In the event of an Emergency Shut Down (ESD) on an LNG vessel carrying out cargo operations in port, can you state 4 items that will be shut down?
Wrong or Missed Data? Click
An ESD 1 can be activated by either ship or shore. An ESD 2 is actived by the shore. An ESD 2 activates everything an ESD 1 does plus it closes valves in the loading arms and disconnects them from the vessel.
LNG1032-261 :
A :
Who activates an ESD 1? And an ESD 2? What does an ESD 2 in addition to ESD 1? Wrong or Missed Data? Click
Prior to arrival at each loading/discharge port.
LNG1032-265 :
A :
How often should the ESD system trips and alarm be tested? Wrong or Missed Data? Click
Yes
LNG1032-266 :
A :
May the terminal have specific requirements for testing the ESD? Wrong or Missed Data? Click
The drench system must protect the accommodation, CCR, compressor room, valves and equipment etc. from heat and spread of fire in the event of a fire/explosion in the cargo area.
LNG1032-270 :
A :
What is the role of the water drenching system (spray system)? Wrong or Missed Data? Click
At least two hand held hoses or combination hoses/monitors are required to cover any part of the cargo deck including all above deck piping.
LNG1032-272 :
A :
What is the required capability of a fixed dry powder type extinguishing system on board an LNG vessel? Wrong or Missed Data? Click
Compressed nitrogen.
LNG1032-273 :
A :
What medium is used as the propellant in fixed dry powder extinguishing systems to discharge the powder? Wrong or Missed Data? Click
Monitors should be fitted to protect the manifold areas and be capable of actuation both locally or remotely.
LNG1032-274 :
A :
Where are monitors fitted? Where could they be activated? Wrong or Missed Data? Click
Float type. Radar type. Capacitance type.
LNG1032-279 :
A :
Can you give 3 cargo tank gauging devices that can be used on board an LNG vessel? Wrong or Missed Data? Click
3.Support Systems (Module 3) - test for Electrician
There must be an independent alarm and ESD trip for very high level completely independent from the gauging system.
LNG1032-280 :
A :
Can the tank gauging system be combined with the high alarm that will close that particular tank's filling valve? Can the tank gauging system be combined with the high high alarm that will cause an ESD?
Wrong or Missed Data? Click
It is the accurate measurement of the volume, temperature and pressure of the cargo loaded or discharged.
LNG1032-285 :
A :
What is meant by Custody Transfer System (CTS)? Wrong or Missed Data? Click
The Float System.
LNG1032-289 :
A :
Which gauging system is independent of all other systems and external sources (e.g. electrical)? Wrong or Missed Data? Click
The Radar System.
LNG1032-290 :
A :
Which gauging system has no electrical cabling or moving parts inside the tank? Wrong or Missed Data? Click
The Capacitance System.
LNG1032-291 :
A :
Which gauging system cannot be removed and overhauled with the tank still in service? Wrong or Missed Data? Click
No.
LNG1032-292 :
A :
Is an area 3 metres aft of the cargo area and 3 metres above the weather deck classed as being in the gas dangerous zone on an LNG carrier as defined by the IGC?
Wrong or Missed Data? Click
An intrinsically safe circuit is one that is designed to produce power at a level that is so low that any spark or thermal effect produced by it, whether there is a fault or not, is incapable of igniting the surrounding flammable gas or vapour.
LNG1032-293 :
A :
What is an intrinsically safe circuit? Wrong or Missed Data? Click
A Zener barrier
LNG1032-294 :
A :
What type of barrier is fitted in an intrinsically safe circuit between the hazardous and non-hazardous areas? Wrong or Missed Data? Click
The shunt diode safety barriers consist of current-limiting resisters and voltage bypassing Zener diodes.
LNG1032-295 :
A :
What are shunt diode safety barriers? Wrong or Missed Data? Click
Videotel CBT LNG Vers 1.0.32 (QUESTIONS & CORRECT ANSWERS)
3.Support Systems (Module 3) - test for Electrician
Intrinsically safe sensor wiring must be kept separate from non-intrinsically safe input wiring and laid in separate conduits.
LNG1032-296 :
A :
What is the requirement about separating intrinsically safe sensor wiring and non-intrinsically safe input wiring? Wrong or Missed Data? Click
The essential requirement for any flameproof equipment is that it must withstand, without suffering damage, any explosion of any prescribed flammable gas that may occur within it under practical conditions of operation, and that it will prevent the transmission of flame which could ignite similar gases which may be present in the surrounding atmosphere.
LNG1032-297 :
A :
What is the essential requirement for any flameproof equipment (Ex d)? Wrong or Missed Data? Click
The enclosure must have sufficient strength to withstand an internal explosion. No joint packing must be fitted in any joints, all must be metal to metal. The holes of any studs or screws must not pass through the wall of the flameproof enclosure.
LNG1032-298 :
A :
Can you give 3 detailed requirements for a Flameproof (Ex d) enclosure? Wrong or Missed Data? Click
This form of protection of electrical equipment on LNG vessels may be used for deck lighting, control cabinets and enclosed spaces of sparking electrical equipment.
LNG1032-299 :
A :
Can you give examples of pressurised electrical equipment (Ex p) that can be used on LNG vessels? Wrong or Missed Data? Click
After maintenance the system must be thoroughly purged prior to switching the equipment back on.
LNG1032-300 :
A :
What is required on pressurised electrical equipment (Ex p) after any maintenance work? Wrong or Missed Data? Click
450 volts
LNG1032-301 :
A :
Above what operating voltage is an HV Electrical Equipment Work Permit required when carrying out maintenance or fault finding on any electrical circuit or equipment?
Wrong or Missed Data? Click
Before a permit is signed and issued, the situation should be assessed by a ship's officer experienced in the work and thoroughly familiar with the relevant hazards.
LNG1032-302 :
A :
What must be done before issuing a work permit for working on high voltage systems? Wrong or Missed Data? Click
Minimum of 200mm
LNG1032-303 :
A :
What is considered to be a safe distance in dry conditions for conductors of 1kV to 11kV potential to ensure that voltage will not "jump" the gap?
Wrong or Missed Data? Click
1) Positive isolation by removal of the isolating device to the "withdrawn" position, padlocked and labelled. 2) Isolator open and locked with padlock. 3) Isolator opened and associated line fuses removed and secured. 4) Isolator open and securely taped.
LNG1032-304 :
A :
Can you state the acceptable methods for safety isolation of an HV circuit starting with the most secure method down to the least secure? A lesser form of isolation is only acceptable where a more secure method is not possible.
3.Support Systems (Module 3) - test for Electrician
8,600,000 ohms (0.38 mA current)
LNG1032-305 :
A :
Infinity resistance is the ideal insulation reading but what would be the lowest acceptable insulation resistance for a 3.3kV machine? Wrong or Missed Data? Click
All circuits that are isolated for maintenance should be earthed. All isolated circuits must be clearly marked with "Danger Do Not Operate" notices. A second person should always be present at the worksite when work is being carried out on HV equipment.
LNG1032-306 :
A :
What are the precautions to take when working on an HV circuit breaker? Wrong or Missed Data? Click
Explosion and arcing is a particular hazard during switching operations and can occur due to equipment defects or build up of dust and dirt.
LNG1032-307 :
A :
Which hazard(s) is/are caused by the operation of an HV circuit breaker? Wrong or Missed Data? Click
Because it can create a path of low resistance and allow leakage currents which could cause the dirt to carbonise, eventually leading to burn out. Also, ventilation ducts may become restricted causing the machine to overheat.
LNG1032-308 :
A :
Why is it important to keep both motors and generators as clean as possible and not allow any dirt to accumulate? Wrong or Missed Data? Click
The control panel, monitor screen and alphanumeric keyboard.
LNG1032-309 :
A :
What is the IAS system (Integrated Automation System) operator interface? Wrong or Missed Data? Click
Power management. Propulsion plant. Cargo and ballast control. Watch call system.
LNG1032-310 :
A :
What is the role of the AIS (Integrated Automation System)? Wrong or Missed Data? Click
Process and system monitoring Event logging and monitoring Control functions (motor control, valve control, PIDs)
LNG1032-311 :
A :
What are the basic functions carried out by the IAS (Integrated Automation System)? Wrong or Missed Data? Click
The IAS is a distributed processing system because the control functions are defined locally in the process stations and not in the operator stations. In the event of failure of control of any equipment then it is possible to change from IAS control to manual local control.
LNG1032-312 :
A :
Why is AIS (Integrated Automation System) defined as a distributed processing system? Wrong or Missed Data? Click
Top light dark and lower two of equal brilliance.
LNG1032-313 :
A :
When paralleling two alternators what is the state of the synchronising lights on a three light synchroniser when the alternators are in phase?
Videotel CBT LNG Vers 1.0.32 (QUESTIONS & CORRECT ANSWERS)
3.Support Systems (Module 3) - test for Electrician
Overspeed Low LO pressure High back pressure or loss of vacuum High rotor displacement
LNG1032-314 :
A :
Can you state 4 situations that will trip a turbo alternator? Wrong or Missed Data? Click
An impulse turbine has fixed nozzles that change the steam flow into high speed steam jets. These jets contain significant kinetic energy, which the rotor blades, shaped like buckets, convert into shaft rotation as the steam jet changes direction. A pressure drop occurs across only the stationary blades with a net increase in steam velocity across the stage.
LNG1032-315 :
A :
How does operate an impulse turbine? Wrong or Missed Data? Click
700-900°C
LNG1032-316 :
A :
What temperature does the air reach on the compression stroke in the cylinder of a diesel engine? Wrong or Missed Data? Click
Turbo chargers are used to compress the air into the cylinders of a diesel engine so that more fuel can be burnt and so more power can be developed.
LNG1032-317 :
A :
What is the use of turbo chargers on Diesel engines? Wrong or Missed Data? Click
In a diesel electric power plant the diesel generators are run at their optimum load for fuel efficiency and are stopped or started depending on the speed required.
LNG1032-318 :
A :
What is the main advantage of a diesel electric power plant? Wrong or Missed Data? Click
Gas turbines have a high power-to-weight ratio.
LNG1032-319 :
A :
What is an important advantage of gas turbines? Wrong or Missed Data? Click
30%LEL
LNG1032-334 :
A :
At what methane concentration will the gas detection sampling points alarm? Wrong or Missed Data? Click
90 seconds.
LNG1032-335 :
A :
What is the minimum length of time a boiler should be purged for prior to attempting to relight a fire? Wrong or Missed Data? Click
The FO boost will come into operation and ignite the FO burners and the steam dump will close.
LNG1032-336 :
A :
What will happen in the event of the main gas valve tripping when the boilers are firing in "gas only mode", with the steam dump open in automatic mode.
3.Support Systems (Module 3) - test for Electrician
The pressure can be vented in a controlled manner by using the vent valve on the forward riser.
LNG1032-337 :
A :
In the event of loss of LD compressors, gas heater or for whatever other reason gas burning is prohibited or greatly restricted, how can the gas pressure in the tanks be controlled?