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
After overhauling a centrifugal pump you have found that the motor electrical connection was wrongly done and pump is rotating in opposite direction. Determine the outcome when the pump is started
Boiler corrosion is prevented above 100 deg by formation of a protective layer inside of
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 lost suction& the suction pressure gauge first started fluctuating and the suddenly started showing positive pressure. The most probable cause leading to pump losing suction could be:
Mechanical seal renew of a pump, the matting face of a seal .
On positive displacement pumps a relief valve is normally required, but in case of centrifugal pumps no such relieving arrangement is fitted. Why?
Corrosion resistance of stainless steel in presence of o2 in aerated water?
Centrifugal pump do not have relief valve why
Cold corrosion in exhaust side of marine diesel engines and fire/smoke side of Boilers occurs mainly due to:
The cooling S.W. temperature rise through the condenser of Fresh water generator has increased. What does it indicate?
A submerged type centrifugal pump is sometimes used as the Main L.O. pump. Why is this?
Phosphor bronze is an alloy consisting of
Which of the following metals can be used as sacrificial anode for protection of Mild Steel
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.
Which one is not self actuated valve
Which of the following statements best describes the process of corrosion?
Combined action of corrosive environment and cyclic stresses may lead to metal or alloy failure . The failure mode is known as:
Auxiliary engine connecting rod bolts should be renewed
During dry dock which of the following should be kept running
Centrifugal pump liquid filled inside casing prior starting why
Submerged pumps are sometimes used as main lo pumps
After closing the drain during the blowing procedure for a glass water gauge, the water cock is opened and the water flows to the top of the glass. Then the steam cock is opened and the water flows down and out of the glass; Which of the following statements are correct?
Turbocharger turbine side water washing of auxiliary engine turbochargers is normally done ______
For a continuous operation diesel engine, a duplex filter unit would be the best arrangement because
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?
What will happen to the motor current if the discharge valve of a centrifugal pump is completely shut off? The current will
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?
Corrosion resistance of Stainless Steel is more in presence of Oxygen or aerated water because :-
Causes of drop in efficiency in fo heater
In reverse osmosis type freshwater generator plants, pretreatment of the feed water is done to:
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?
Lantern ring in centrifugal pump is located
Wet corrosion in the process which is
Polymer treatment is restricted only to low pressure boilers because
Which of the following valves are not designed normally for bi-directional flow(return type or two-way flow valve)?
The amount of current needed for hull protection in case of ICCP system for a particular ship will be most effected by:-
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: