In a shell and type M/E L.O. cooler, the temperature of L.O. is controlled by an automatic temperature control valve. Out at sea with M/E running at sea load it is observed that the temperature control valve opening to the cooler is increasing day by until it becomes 100% open to the cooler. The L.O. outlet temperature _______________ after the above condition has reached
Which of the following statements is true about compressor air coolers?
A grease lubricated ball bearing or roller bearing will run cooler if the grease
Cavitation of centrifugal pump
You have overhauled a centrifugal pump and while assembling forgot to install the o-ring between the sleeve (provided in way of gland packing) and the shaft. What impact does this have?
If a reciprocating air compressor has a knock occurring in frequency with its operating RPM, the cause is probably ____________.
Which of the electrical instruments can be used without interrupting a live electrical circuit
If the suction filter of the ballast pump is blocked during deballasting it will be:
WHEN BOTH PUMPS OF STEERING GEAR ARE IN OPERATION
Which of the following statements is true?
A __________ type pump is normally used as a Boiler feed pump for Auxiliary Boilers on modern merchant ships
You have valves of same bore diameter but of different types. Which of the following is arranged in the decreasing order closing torque required for giving a perfect seal?
You have dismantled a centrifugal pump having a double entry impeller, but forgot to do the markings while dismantling. During installation what will you do?
Which series is used for determining the suitable electrode for cathodic protection of metal
In a centrifugal pump the fluid enters
Throttling of suction v/v in screw p/p
You have lined up # 1 main fire pump for supply to one of the deck hydrants. You have personally checked opening of all the required valves and start the pump. The pump discharge shows a pressure of about 5 bar, but the deck hydrant doesnt get any water. You line up # 2 fire pump and get water on the deck hydrant when the pump discharge pressure shows only 2.5 bar. State the reason why # 1 Fire pump was unable to send water to the deck hydrant?
Metal cladding provides protection to the metal essentially for the life of ship because
Three centrifugal pump are running in parallel and back pressure is increased flow ratio will reduce
Oil emulsification in engine lubricating oils will tend to ________________.
One cause of leaky valves in a low pressure air compressor may be attributed to __________.
The direction of centrifugal pump depends upon what
The color of the refrigeration oil can indicate various operating conditions of the compressor/ refrigeration system in which it is used. Black oil can be an indication of _____________________.
All other conditions remaining constant, when centrifugal pump is changed over for pumping a liquid of higher specific gravity, the discharge head of the pump at the rated capacity will
It is said that strength of steel depends upon carbon percentage, which one of the following steel have max strength
Intercoolers in multistage compressors ________
Cavitation erosion occurs due to
Correct sequence of metals in increasing order of nobility in galvanic series:
Not preventing cold corrosion in M/E component
Piping is sized by its nominal _________________.
A thermostatic expansion valve is designed to respond to _____________.
Which of the following can be provided galvanic protect to stainless steel
Whenever a F.O. heater is put into use it should first be ________ by using the ___________to prevent ____________. Fill in the blanks using the correct set of options
Moisture in a refrigeration system
Lifeboat winches are required to be inspected and an entry made in the logbook. How often is this inspection required to be made?
Many diesel engines have pistons with conceive heads to _______________.
Why are removable sleeves installed on centrifugal pump shafts?
Automatic/manual recirculation valve provided on the seawater overboard are provided……………………….
To avoid Cavitation of centrifugal pump
The exposed portion of the outboard propeller shaft is protected against seawater corrosion by __.
Emergency fire pump has been lined up for supplying to fire hydrant on deck.As soon as the pump is started the vacuum pump engages. The suction of the pump goes into high vacuum but the pump discharge pressure remains zero, and the vacuum pump doesnt disengage?What is the most probable cause for the pump not to take suction?
Steel carbon equivalent > 0.5%
Cylinder head tightening of auxiliary engine should always be done in single stage and as per start??
Screw pump is normally used for
The purpose of balancing holes on a single entry closed type impeller of a centrifugal pump is:
Which of the following types of tubes in air compressor coolers would be self-compensating for expansion?
Which of the following problems may be encountered by using an oil having a viscosity higher than that specified for an operating hydraulic system?
The gasket and the broken studs have been replaced on a tank manhole cover. Which of the following methods is satisfactory for testing the repair?
If a radial piston hydraulic pump fails to deliver rated fluid volume, the cause can be _______________.