1|Page
MACHINIST MATE EXAMS, PRACTICE EXAM AND
STUDY GUIDE EXAMS WITH ACTUAL CORRECT
QUESTIONS AND VERIFIED RATIONALES
ANSWERS 2024 (NEWEST) ALREADY GRADED A+
What at prohibits any person to discharge oil from any water borne vessel or ashore or offshore facility
into/upon certain waters and established restrictions within contiguous zone
Federal water pollution act 1970
What are the two principal parts of an air register?
Diffuser, air foils
What is the max rpm differential on two FOB operating in parallel?
300 rpm
What is the purpose of scavenging air connection located on soot blower head?
It supplies air to soot blower element to prevent the combustion gases from backing up into soot blower
head or steam piping
An insulating block is capable of withstanding surface temp of what?
1500 degrees
If ignition fails to occur within two or three seconds, what action must be taken?
Shot burner fuel oil manifold valve safety shit off device and investigate cause
What is the purpose of the gland dealing system?
It prevent steam from leaking out of the main engine and from air entering
How are flanges installed in a non ferrous system?
Brazing
How often are fuel tanks emptied to reduce heavy sludge deposits?
Every 12 months
What lubricated corrugated ribbon packing?
Graphite
What must be done to lube oil coolers that are online more than 24 hours?
Drain seawater side
,2|Page
What material are oil deflectors made from?
Aluminum or bronze
DFT will maintain dissolved oxygen context at or below what level?
15 ppm
What fuel oil test uses hydrazine?
API gravity
What device is installed on main engine to prevent leakage or steam from engine?
Labyrinth packing
If rotary pumps are operated at higher than normal speed what will occur?
Erosion and excessive wear
When shall safety valve gauge be placed on boiler prior to safety settings?
When steam drum pressure is 100 to 200 psi below lower valve settings or 75% or working pressure,
whichever is higher
To obtain max effective sealing of labyrinth packing the tip width of packing teeth should be maintained
within what parameter?
.010"
Idle line shaft bearing oil must be sampi 60 At what periodicity?
Weekly
Transverse diametrical pitch of reduction gear
Ratio of number of teeth to number of inches of pitch diameter
What type of reduction gear would you expect to find in aux type shop?
Tandem articulated
Double reduction
With one or more inputs
Typical end play with cold engine is what?
.008-.014"
What type of gauge is used to measure clearance between high pressure and low pressure turbines?
Taper gauge
Chloride is an indication of what type of contamination?
Sea water
,3|Page
How are steel flanges installed in systems?
Welding
What type of corrosion is caused by shore water contamination?
Caustic
Max silica content of shore source feed water
.20 ppm
What is primary source of silica contamination?
Poor quality shore feed water
Which dishwasher is fully automatic?
3 tank machine
Max moisture content of an oil sample drown from centrifugal compressor?
100ppm
Main condenser is what type of heat exchanger?
Cross flow
When stripping fuel oil tanks, system is aligned to draw off how many gallons of fuel?
150-300 gallons
Time limit on sodium nitrate wet lay up?
No time limit
What device is installed on main engine thrust bearing to indicate flow?
Sight flow indicator
Boiler full power capacity will be affected if what percent of generating tubes are plugged?
>5%
When warming up a propulsion turbine the turbine should be rotated with steam at which interval?
2-3 mins
Main reduction gear dehumidifier system must be checked at what frequency for correct operation?
Daily
All boiler tubes are identified in what manner?
Tube rows by lettering
Individual tubes in each row by numbers
, 4|Page
SSTGs are fitted with what type of governor?
Constant speed
What is installed on a pump shaft to prevent total replacement of shaft due to excessive wear and
scoring
Shaft sleeves
Minimum steam atomization temp at the burner front is what?
370 degrees
What is the purpose of apron plates ?
To form annular passageway for steam and water mixture from generating tubes to separators
What are the two main parts of a reciprocating pump?
Waters end
Steam end
Three authorized cleaning methods for removing soft deposits?
High pressure water jet
EDTA
Power driven wire brush
How much desiccant is used for a proper dry lay up?
16lbs for every 1000 gallons of cold water capacity
What chapter deals with pollution control?
NSTM 593
What is the min water temp used for boiler hydrostatic testing?
70
How is the operation of a bellows type steam trap controlled?
Expansion of the vapor of volotize liquid which is enclosed in the bellows
What is the cooling source for inline de super heater?
Feedwater
Automatic unloading valves are installed to exhaust to what major component?
Main and aux condensers
On spring loaded reducing valve what determines position of aux valve?
Position of controlling diaphragm
MACHINIST MATE EXAMS, PRACTICE EXAM AND
STUDY GUIDE EXAMS WITH ACTUAL CORRECT
QUESTIONS AND VERIFIED RATIONALES
ANSWERS 2024 (NEWEST) ALREADY GRADED A+
What at prohibits any person to discharge oil from any water borne vessel or ashore or offshore facility
into/upon certain waters and established restrictions within contiguous zone
Federal water pollution act 1970
What are the two principal parts of an air register?
Diffuser, air foils
What is the max rpm differential on two FOB operating in parallel?
300 rpm
What is the purpose of scavenging air connection located on soot blower head?
It supplies air to soot blower element to prevent the combustion gases from backing up into soot blower
head or steam piping
An insulating block is capable of withstanding surface temp of what?
1500 degrees
If ignition fails to occur within two or three seconds, what action must be taken?
Shot burner fuel oil manifold valve safety shit off device and investigate cause
What is the purpose of the gland dealing system?
It prevent steam from leaking out of the main engine and from air entering
How are flanges installed in a non ferrous system?
Brazing
How often are fuel tanks emptied to reduce heavy sludge deposits?
Every 12 months
What lubricated corrugated ribbon packing?
Graphite
What must be done to lube oil coolers that are online more than 24 hours?
Drain seawater side
,2|Page
What material are oil deflectors made from?
Aluminum or bronze
DFT will maintain dissolved oxygen context at or below what level?
15 ppm
What fuel oil test uses hydrazine?
API gravity
What device is installed on main engine to prevent leakage or steam from engine?
Labyrinth packing
If rotary pumps are operated at higher than normal speed what will occur?
Erosion and excessive wear
When shall safety valve gauge be placed on boiler prior to safety settings?
When steam drum pressure is 100 to 200 psi below lower valve settings or 75% or working pressure,
whichever is higher
To obtain max effective sealing of labyrinth packing the tip width of packing teeth should be maintained
within what parameter?
.010"
Idle line shaft bearing oil must be sampi 60 At what periodicity?
Weekly
Transverse diametrical pitch of reduction gear
Ratio of number of teeth to number of inches of pitch diameter
What type of reduction gear would you expect to find in aux type shop?
Tandem articulated
Double reduction
With one or more inputs
Typical end play with cold engine is what?
.008-.014"
What type of gauge is used to measure clearance between high pressure and low pressure turbines?
Taper gauge
Chloride is an indication of what type of contamination?
Sea water
,3|Page
How are steel flanges installed in systems?
Welding
What type of corrosion is caused by shore water contamination?
Caustic
Max silica content of shore source feed water
.20 ppm
What is primary source of silica contamination?
Poor quality shore feed water
Which dishwasher is fully automatic?
3 tank machine
Max moisture content of an oil sample drown from centrifugal compressor?
100ppm
Main condenser is what type of heat exchanger?
Cross flow
When stripping fuel oil tanks, system is aligned to draw off how many gallons of fuel?
150-300 gallons
Time limit on sodium nitrate wet lay up?
No time limit
What device is installed on main engine thrust bearing to indicate flow?
Sight flow indicator
Boiler full power capacity will be affected if what percent of generating tubes are plugged?
>5%
When warming up a propulsion turbine the turbine should be rotated with steam at which interval?
2-3 mins
Main reduction gear dehumidifier system must be checked at what frequency for correct operation?
Daily
All boiler tubes are identified in what manner?
Tube rows by lettering
Individual tubes in each row by numbers
, 4|Page
SSTGs are fitted with what type of governor?
Constant speed
What is installed on a pump shaft to prevent total replacement of shaft due to excessive wear and
scoring
Shaft sleeves
Minimum steam atomization temp at the burner front is what?
370 degrees
What is the purpose of apron plates ?
To form annular passageway for steam and water mixture from generating tubes to separators
What are the two main parts of a reciprocating pump?
Waters end
Steam end
Three authorized cleaning methods for removing soft deposits?
High pressure water jet
EDTA
Power driven wire brush
How much desiccant is used for a proper dry lay up?
16lbs for every 1000 gallons of cold water capacity
What chapter deals with pollution control?
NSTM 593
What is the min water temp used for boiler hydrostatic testing?
70
How is the operation of a bellows type steam trap controlled?
Expansion of the vapor of volotize liquid which is enclosed in the bellows
What is the cooling source for inline de super heater?
Feedwater
Automatic unloading valves are installed to exhaust to what major component?
Main and aux condensers
On spring loaded reducing valve what determines position of aux valve?
Position of controlling diaphragm
