Q- A fluctuating and unsteady vacuum in an evaporator may be caused by _____________.
1. wet steam entering the air ejector nozzle
2. pinhole leaks in the evaporator tube nests
3. rapid scaling on the evaporator tube nests
4. high water levels in the last effect
Q- Which of the main shaft segments listed below, that are connected with the main engine, are coupled to the tail shaft flange?
a. Thrust shaft
b. Stern-tube shaft
c. Intermediate shaft
d. Crank shaft
Q- Piping cross-sections over 30 cm in diameter are sized by the __________.
a. inside diameter
b. wall thickness
c. outside diameter
d. threaded diameter
Q- 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? (single answer)
e) It will not affect the pump in any way
f) It will cause leakage of fluid(air/water) in between the shaft and the sleeve and will affect the pump performance
g) It will not affect the pump performance n any way but will corrode the shaft between the o-ring and shaft
h) It will cause dynamic imbalance of the shaft
Q- Correct method of greasing a centrifugal pump bearing is:
A. To pump the grease until you feel high back pressure on the Grease pump
B. To pump the greasefor 3-4 pumping strokes of Grease pump for each bearing
C. To pump the grease when the pump is stopped and drain any old grease at the same time by opening the drain plug, giving only 3-4 pumping strokes on Grease pump for each bearing. the drain plug should then be replaced
D. To pump the grease when the pump is running and drain any old grease at the same time by opening the drain plug, until all the old grease is removed and new grease starts coming out of the drain, repeating same for each bearing. the drain plug should then be replaced
Q- Why is it essential to renew turbocharger bearings after a preset number of hours of running even if the bearings are in seemingly perfect condition?
A. Because they are prone to failure due to prolonged exposure to high temperature conditions.
B. Because they are subject to cyclic loading and are prone to failure due to metal fatigue.
C. It is not essential to renew if condition monitoring suggests perfect condition.
D. Lube oil contamination is bound to occur and affect the condition of the bearings.