"Q" Tests- General Subjects Flashcards
If both the shell-and-tube lube oil cooler and shell-and-tube jacket water cooler of a diesel engine are seawater cooled, what statement is true?
Seawater flows through the tubes of both the lube-oil and jacket-water coolers.
If a heat exchanger is designed to condense refrigerant vapor using central cooling fresh water as a condensing medium, what statement is true?
The refrigerant vapor loses latent heat, the central cooling fresh water gains sensible heat.
What type of flow pattern would be associated with a forced-convection finned-coil heat exchanger such as an air-cooled hydraulic oil cooler?
Cross flow
If a seawater-cooled shell-and-tube lubricating oil cooler has the seawater inlet and outlet connections on the opposite end water boxes, in terms of the number of passes, what statement is true?
The tube-side fluid flow pattern is single-pass.
The general purpose of a heat exchanger is to __________.
heat, or cool one fluid by means of another fluid
Pressure in an operating hydraulic system is developed __________.
by resistance to the fluid flow through the system
In the system illustrated, which of the following readings should be indicated on the pressure gage, if the load (x) is 8000 lbs (3632 kg) and the piston area (y) is 10 sq. in (64.5 sq. cm)? GS-0062
800 psi (56.31 kg/cm2)
Which characteristic or condition will have the greatest effect on increasing a hydraulic oil’s viscosity?
Pressure
The by-products of oxidation, as a result of water contamination of hydraulic oil, are generally __________.
gums, varnishes, and acids
Energy losses occurring in a hydraulic system are ultimately absorbed by the __________.
atmosphere as heat
The illustrated hydraulic pump graphic symbol is used to depict a __________. GS-0098
combined, pump unit
An arrow superimposed on a hydraulic graphic symbol at approximately 45°, as shown in the illustrated figures A, B, and C, indicates the component __________. GS-0068
can be adjusted or varied
Item “F” shown in the illustration represents two hydraulic pumps that are __________. GS-0103
manually operated with one located in the engine room and the other in the shaft alley of the water tight door
The illustrated hydraulic pump graphic symbol is used to depict a/an __________. GS- 0097
double pump unit
Item “B” shown in the illustrated hydraulic circuit is used to __________. GS-010
shut down the remotely operated electric motor driven pump when the watertight door has closed
Energy imparted to the hydraulic fluid in an operating hydraulic system is stored in the __________.
accumulator
The component which is used to thoroughly separate small, fine, dust-like particulate contamination from hydraulic fluid is a/an __________.
filter
Of the hydraulic tubing fittings illustrated, the flared fitting for high pressure use is represented by figure __________. GS-010
A or B
The portion of a hydraulic hose that determines its overall strength is the __________.
braided inner layer(s)
The discharge capacity of the axial piston hydraulic pump, shown in the illustration, is __________. GS-0058
fixed by the pump housing angle
To convert a vane type hydraulic pump to a hydraulic motor, which of the following would have to be done?
Provide small springs between the vanes and the base of the vane slots.
In a hydraulic system using the device illustrated, the high pressure return is provided by __________. GS-0118
A
Return lines in a non-pressurized hydraulic system reservoir should enter the tank well below the fluid surface level to __________.
prevent foaming
Which of the following direct-reading pressure gauges is capable of measuring and displaying both positive and negative pressures?
Compound gauge
Which of the following direct-reading pressure gauges is capable of measuring and displaying two pressures simultaneously?
Duplex gauge
Which of the following direct-reading pressure gauges is capable of measuring two pressures and displaying the difference between the two?
Differential pressure gauge
Which of the following direct-reading gauges would most likely be used in the application of a pump suction pressure gauge?
Compound gauge
If a standard bourdon tube type pressure gauge that is designed to measure and display gauge pressure reads 43.8 psig, what would be the equivalent absolute pressure?
58.5 psia
What type of direct reading thermometer works on the principle of thermal volumetric expansion of a liquid as the temperature rises and features a linear scale?
Liquid-in-glass thermometer
What type of direct reading thermometer works on the principle of differential expansion of dissimilar metals as the temperature rises and features a rotary dial scale?
Bimetallic thermometer
What is the application for a temperature measuring device known as a thermocouple pyrometer?
Extremely high temperature applications such as boiler or engine exhaust temperatures.
If the mercury has become separated in a liquid-in-glass thermometer, what can be done to correct this situation?
After removing the thermometer, hold the thermometer by the lower end and try to recombine
the mercury by several full arm swings.
What statement is true concerning the vent pipes and sounding tubes associated with a vented tank?
The vent pipe attaches to and ends at an opening at the top of the tank, and the sounding tube passes through the tank top and extends almost to the tank bottom.
What statement best represents the characteristics of an innage tape and bob for the purposes of taking a vented tank sounding?
The bob has a pointed end and sinks in the liquid when lowered by the tape.
What statement best represents the characteristics of an ullage tape and bob for the purposes of taking a vented tank sounding?
The bob has a cupped end and floats on the surface of the liquid when lowered by the tape.
What statement best represents the characteristics of innage and ullage tank soundings?
Innage is the distance between the surface of the liquid and the bottom of the tank, and ullage is the distance between the surface of the liquid and the top of the tank.
When determining the level of a potable water hydro pneumatic header tank fitted with a tubular sight glass, what must be taken into consideration?
The actual water level in the hydro pneumatic header tank is identical to the level shown in the
sight glass.
Which of the following measurements would be an example of total flow?
cubic meters
Which of the following measurements would be an example of flow rate?
cubic meters per hour
Which of the following is an example of a flow meter which has associated with it a float for flow indication purposes?
A variable volume flow meter (rotameter)
For any piece of equipment requiring lubrication, what is the single most important lubricating oil property in meeting the operating conditions?
Viscosity
For a lubricating oil, what is the relationship between viscosity and temperature?
As the temperature of a lubricating oil increases, the viscosity of the lubricating oil decreases.
What statement is true concerning viscosity index as it applies to lubricating oils?
An oil with a high viscosity index would have a relatively low rate of change of viscosity as the temperature changes.
What type of grease is the most commonly used aboard ship?
Lithium-based grease
If an engine lubricating oil’s viscosity is given as 20W-50, what does this mean?
The oil is formulated to meet the low temperature requirements of SAE 20W oil and the 100oC (high) temperature requirements of SAE 50 oil and as such is a year-round oil.
An air compressor is equipped with an intercooler and an after cooler to __________.
increase compressor efficiency and economy
For any given volume of compressed air produced by a multistage air compressor, interstage cooling will __________.
decrease the power required for compression
The usual method of unloading a low pressure air compressor at start-up is accomplished by __________.
holding the suction valve open