Auxillary Flashcards
What device transfers heat from one fluid to another?
Heat exchanger
What is the most common type of heat exchanger used in the Coast Guard?
Shell and tube
The fin and tube heat exchanger is an air cooled condenser in AC/R systems. What increases the surface area and aids in transferring heat?
The fins
How does a condenser work in an AC/R system?
It changes refrigerant from a vapor to a liquid as heat is transferred from the vapor to the surrounding water
Corrective maintenance is conducted conditionally on heat exchangers when?
Fluid is leaking from the heat exchanger or the system is not operating within normal parameters
Before draining, cleaning, and inspecting a heat exchanger that is part of an AC/R system who must recover the refrigerant?
AN EPA certified technician
What is generally the best method for cleaning tubes because it removes all soft fouling?
High-pressure water jet
Where can you find all the information you need about heat exchangers?
NSTM, Chapter 254
Backflushing is only required on what kind of plate type heat exchanger?
Seawater cooled
What do you never want to do on a plate type here exchanger while it is running?
Tighten or loosen the plate pack
Exercise extreme caution when handling plates because?
The edges can be extremely sharp. Always wear gloves
How do you want to remove the plates and a plate type heat exchanger?
Tilt them toward the rear of the unit until the top slot is free of the guide bar.
How do you want to clean the plates on a plate type heat exchanger?
With a fiber brush and clean water
What is the primary goal for expecting plate type heat exchangers?
To detect for leaks
Not more than how much percent of a heat exchanger can be plugged before it has to be replaced?
10%
How much time do you allow that he served here after you replace the gaskets?
12 hours
What are the two types of auxiliary boilers?
Fire tube and water tube boilers
Third vantage of fire two boilers are what?
Inexpensive to build
Simple to operate
And less maintenance
The disadvantages of the fire tube boilers is what?
Long warm-up time
And weight of the unit compared to the amount of steam produce
The advantages of the water tube boilers are what?
Les warm-up time in the ratio of size and weight to steam produced
The disadvantages of the water tube are what?
Requires more maintenance and are expensive to build
The temperature at which water boils is called what?
Boiling point or saturation temperature
As Steve gives up his he returns to its liquid state it is called what?
Condensate
What is used in the auxiliary boiler to produce a controlled fire in the combustion chamber?
The burner unit
What is installed in the tank to prevent the pump motor and solenoid valve from becoming energized in the event the condensate tank water is low?
Float switch
During normal operation of a auxiliary boiler the level in the sight glass should be what?
Half full
What is an alternative method for checking the boiler water level in the event the sight glass is inoperative?
Tri-cocks
When are blow downs done?
Daily or when the total dissolved solids’s is above 1000 ppm
On an auxiliary boiler what is the primary device to control the start and stop of the burner?
Operative pressure control switch
What safety device is designed to shut down the burner in the event the operative pressure control does not secure the boiler at the normally prescribed cut out. of 26 PSI?
High limit pressure control switch
What are the three general warning lights on the control panel on the boiler?
RED = Flame out
BLUE = Low water
WHITE = Power on light
What is installed on the boiler to prevent short cycling due to changes in water level due to the ships motion?
Adjustable time delay
What is the electrical control that controls the start up and shutdown sequence of the boiler?
Flame safeguard control (FSC)
What is the device where a high-voltage spark is created which ignites the fuel delivered from the nozzle?
Ignition electrode
On a boiler what delivers a high quantity of air for combustion?
Squirrel cage blower
The amount of air delivered to the combustion chamber is controlled by the means of what?
A manually adjusted air damper
When adjusting the air damper it should be marked how on the blower housing for future reference?
Scribed
What does the stamped number on the side of the fuel nozzle mean?
The first number indicates your mouth to fueled that passes through it in gallons per hour
The second number is the angle of the spray
