On positive displacement pumps a relief valve is normally required, but in case of centrifugal pumps no such relieving arrangement is fitted. Why?
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?
Which of the following valves are not designed normally for bi-directional flow(return type or two-way flow valve)?
The cooling S.W. temperature rise through the condenser of Fresh water generator has increased. What does it indicate?
Ballast pumps have individual suction filters provided. Onboard your ship it is seen that during ballasting the ballast pump suction is getting blocked very frequently during ballasting. You should:
Older tankers were designed to carry clean ballast in cargo tanks(CBT). Assume that Ballast Water and the crude oil have same density.While pumping out crude oil the motor of the cargo pump for CBT will draw current compared to when pumping Ballast given that the same discharge pressure is maintained in both the cases.
What will happen to the motor current if the discharge valve of a centrifugal pump is completely shut off? The current will
Deballasting of Fore peak tank, which was full, was commenced. The suction pressure was positive until the sounding was 2.0 m and the gland packing was found leaking. Below 2.0m sounding the suction went into slight vacuum and the leakage of gland stopped. Deballasting was normal until the tank sounding was 150 cm when the pump started showing positive pressure. The most probable cause leading to pump losing suction could be:lost suction& the suction pressure gauge first started fluctuating and the suddenly
The Non-return discharge valve of one of the Main Sea water pumps was found badly leaking in closed position. Upon inspection it was found damaged beyond repair. You have a new valve of same specification except that it is a return type valve. Which of the following is the correct practice?
For a globe valve in operation it is seen that the gland packing is leaking when the valve is kept in throttled position. Tightening of the gland packings doesn???t help much.Second Engineer decides to keep the valve fully open and it is seen that the Gland packing leakage suddenly stops!! The most probable reason why the leakage stopped is (choose best & most logical alternative):
Combined action of corrosive environment and cyclic stresses may lead to metal or alloy failure . The failure mode is known as:
In aerobic sewage treatment units, it is paramount that the air blower runs at all times. Which of the following would constitute an ideal alarm for failure of belt driven blowers?
You have to open up a F.O. heater for cleaning. As 2nd engineer has reported that the valves of F.O. inlet is not holding, the M/E was changed over to D.O. during arrival port and the F.O. system was shut down after arrival port. You have been instructed to open up the heater. What will you do?