OCTCO/OCTF Exit Exam • Set 3 Question 4 of 30
A centrifugal bilge pump requires priming?
✓
Direct Answer
Option C: Due to the inability of this type of pump to lift water to cover the suction(eye)) of the empeller.
Centrifugal pumps are not self-priming because they cannot create a sufficient vacuum with air/vapour to draw liquid into the impeller eye; hence, priming is required to fill the casing and suction.
All Options
A
In order to overcome the potential energy of water in the discharge line.
B
Primarily to lubricate the shaft.
C
Due to the inability of this type of pump to lift water to cover the suction(eye)) of the empeller.
(Correct Answer)
D
To initially unload the pump by having its head pressure equal to discharge pressure
Detailed Explanation & Context
Centrifugal pumps are not self-priming because they cannot create a sufficient vacuum with air/vapour to draw liquid into the impeller eye; hence, priming is required to fill the casing and suction.
Relevant Framework: STCW 2010 Manila Amendments • DG Shipping E-Learning & Exit Exam Standards • Oil and Chemical Tanker Cargo Operations (OCTCO/OCTF).
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