CARGO OPS ; Cargo Systems, COW, Definitions, Tanker Work Flashcards
What is a characteristic of all centrifugal cargo pumps?
Decreasing the speed of rotation will decrease the discharge pressure
The system of valves and cargo lines in the bottom piping network of a tank barge that connects one section of cargo tanks to another section is called a __________.
crossover
What is NOT an advantage of centrifugal pumps over reciprocating pumps?
They require priming for stripping
The purpose of a bilge well is to __________.
collect water to be pumped out
What is TRUE of pressure/vacuum valves?
They are designed to provide for the flow of small volumes of tank atmospheres caused by thermal variations in a cargo tank
They should operate in advance of the pressure/vacuum breakers.
They should be kept in good working order by regular inspection and cleaning
When stripping a tank, excessive air in the suction line may cause __________.
loss of suction
Which statement is TRUE of centrifugal pumps aboard tankers?
They are gravity-fed
Which statement about a centrifugal cargo pump is TRUE?
It must have a positive suction
Which statement is TRUE of centrifugal pumps aboard tank vessels?
They are gravity fed
Which pump must always be primed?
Centrifugal pump
The valve on the discharge side of a cargo pump on a tank vessel will usually be a __________.
check valve
To insure proper seating when closing a valve on a tank, the valve should be __________.
closed, opened half a turn, and then closed again
Centrifugal pumps have what advantage(s) over reciprocating pumps?
They are less expensive
They are smaller for equivalent pumping ability
They pump more cargo in less time
What is the purpose of the relief valve of a cargo pump?
permits the return of cargo to the suction side of the pump
A deepwell pump is a type of __________.
centrifugal pump
All of the following steps are taken in starting a centrifugal pump.
Check the lubrication system
Vent the pump casing
Open the pump suction and discharge valves
What is NOT a step taken in starting a centrifugal pump?
set the relief valve
What is the purpose of pressure-vacuum relief valves?
To maintain a tank or void at atmospheric pressure
Cargo pump relief valves are piped to the __________.
suction side of pumps
A relief valve for a cargo pump is generally installed __________.
between the pump and discharge valves
The system of valves and cargo lines in the bottom piping network of a tanker that connects one section of cargo tanks to another section is called a __________.
crossover
A single fitting installed in a pipeline that either blanks off the pipe or allows a full flow passage of a liquid through the pipe is referred to as a __________.
spectacle flange
The main function of a stripping system is to __________.
discharge liquid left in the cargo tanks after the main pumps have discharged the bulk
What will NOT increase friction of a liquid flowing in a pipe and cause a loss of suction head?
slowing the pumping rate
The fitting at the end of a cargo line in a tank that allows suction to be taken close to the bottom of a tank is a __________.
bell-mouth
What is LEAST likely to be used to strip a cargo tank?
centrifugal pump
The pipe used to connect two separate piping systems on a tank vessel is known as a __________.
crossover
The piping that routes an oil cargo from the manifold directly to a cargo tank and serves only one tank is known as a __________.
tank drop
The main underdeck pipeline on a tankship is connected to individual tanks by __________.
branch lines
The piping that routes an oil cargo from the manifold to underdeck pipelines is known as a __________.
line drop
Which characteristic is an advantage of a butterfly valve as compared to a gate valve?
quick operation
Which characteristic is an advantage of a butterfly valve as compared to a gate valve?
easier operation
What is an advantage of a gate valve over a butterfly valve?
less frequent maintenance
Which method should be used to warm up the pump turbines prior to discharge?
Shut the discharge valve and run the pump at low speed
Which statement is TRUE concerning deep well self-priming pumps?
stripping systems are generally eliminated for the purposes of cargo handling
Insulating flanges minimize the dangers arising from __________.
accumulations of electro static charges
You have completed a crude oil wash. What action should be taken with the oil in the lines running to the washing machines?
open a COW nozzle forward and one aft and drain the line into the after tank by gravity
When cleaning a tank by the Butterworth process, you should begin to pump out the slops __________.
when the process is started
When cleaning cargo tanks with portable machines, how is the machine grounded?
The water supply hoses contain internal wires that act as conductors
You are cleaning the tanks after carrying a cargo of crude oil. Which statement is TRUE?
steam cleaning and water washing are both capable of generating electro static charges within a tank
You are planning to use a crude oil washing system. What precaution must be taken with the source tank for the washing machines?
at least one meter must be decanted from the source tank
You are planning to use the crude oil washing system on your tankship. What is required to prevent electrostatic buildup in the tanks?
The source tank for the tank cleaning machines must have at least one meter decanted from it
You have water washed your cargo tanks using the fixed machines. What should you do before using portable machines to clean areas screened from the wash of the fixed machine by structural members?
ventilate the tank to eliminate any electrostatically charged mist
In order to reduce the accumulation of static electricity while loading petroleum products, you should __________.
start to load slowly
Static electricity may be built up by the __________.
Spraying or splashing of petroleum
Settling of solids or water in petroleum
Flow of petroleum through pipes
Which product is most likely to accumulate static electricity?
lubricating oil
The complete details of a crude oil washing system aboard your vessel, including the operating sequences and procedures, design characteristics, a description of the system, and required personnel will be found in the __________.
Crude Oil Washing Operations and Equipment Manual
When tank cleaning with a portable machine, the weight of the machine is suspended from __________.
the supply hose
Before a tank is to be crude oil washed, the oxygen content in the tank must be measured at a position __________.
one meter from the deck
What is NOT a requirement for the safe and effective use of a crude oil washing system?
Use portable washing machines to reach areas obscured by structural members in the tanks
What are requirements for the safe and effective use of a crude oil washing system?
Strip all tanks and remove the bottom residue
Use an inert gas system while washing tanks
Decant one meter from the source tank fro the tank cleaning machines
Which step is NOT generally taken when gas-freeing a tank?
application of degreasing solvents