CARGO OPS ; Cargo Systems, COW, Definitions, Tanker Work Flashcards
(131 cards)
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