Q- In case of failure of the control system of a centrifuge, the correct sequence for manually desludging a purifier would be-
A. Stop feed-give sealing water-close sealing water –shut operating water-open and close desludging water quickly
B. Stop feed- shut operating water-open and close desludging water quickly
C. Shut operating water-stop feed- open sealing water for a short time then close-open and close desludging water quickly
D. Shut operating water- stop feed- open and close desludging water quickly
Q- Centrifugal pump change over for pumping liquid of high specific gravity the discharge at the rated capacity will be
d. Convert 50%
Q- screw pump generally?
a. slow speed
Answer-A (But in some cases it is medium speed also)
Q- The type of corrosion normally occurring in cooling Fresh Water systems of Marine Diesel Engines is :
A. Stress corrosion
B. Hot corrosion
C. Bimetallic corrosion
D. Selective Phase corrosion
Q- Normally so called??? Single screw pumps??? Are used as sludge pumps in engine room. What is correct technical name of these pumps?
e) Snake pump
f) Screw pump
g) Progressive cavity pump
h) Gerotor pump or gyrator pump
Q- which of the not self actuating valve.
a. check valve
During cleaning of the sea water suction filter, it was found that at some places the mesh size has increased either due to corrosion or due to mechanical Damage. What action is required?
A. No action is required, it is quite normal for sea water filters to get corroded and it will not effect the pump in anyway
B. Keep the pump which is having corroded filter on standby use while keep using the other pump. Meanwhile order for the new filter
C. The pump can be run without filter for a short time, while the filter is being repaired
D. Permanent repairs to the filters should be carried out before putting it into service, or it should be replaced with good spare filter
Answer-DMarine Aux 2013 Ojective Papers