Mn Exam Prep Questions Flashcards
Which formula is used to determine the efficiency of the boiler based on heat absorption?
Output divided by the input
How many ways can heat be transferred?
3
How many types of heat are there?
3
How many different types of drafts are there ?
3
How many different types of boilers are there?
3
How many different types of low water fuel cut offs are in general use?
3
True or False?
A (RPZ) “reduced pressure zone” or back flow preventer prevents contaminated water from entering the domestic water supply.
True
Boiler and boiler fittings used in the state of Minnesota must be constructed to what code?
A.S.M.E.
What is the unit called that controls the starting and stopping of the burner by sensing the temperature of the water in a hot water boiler?
Aqua stat
Heat can be transferred in 3 ways and they are?
Conduction , Radiation , Convection
The first sequence in the series of automatic burner control is?
Purging
Air that mixed with the fuel at / or in the burner is called?
Primary air
Can a low water condition occur in a hot water heating type boiler?
Yes, for numerous reasons
Other than a safety relief valve… What other safety device should be installed on a hot water heating boiler ?
Low water fuel cutoff
What is the internal resistance to the flow of fuel oil?
Viscosity
Each boiler in a battery (piped together sharing the same common header)must have:
A main steam stop
What removes air from a hot water boiler system?
Air control
When a hydrostatic test of a boiler exceeds the maximum allowable working pressure, each safety valve ( if left attached to the boiler) should:
Have its valve disc held to its seat by means of testing clamp or “gag”
Why is a safety valve sealed?
To prevent tampering with pressure and capacity
Oxygen in a boilers water can cause?
Corrosion
In a steam boiler system the unit that turns the burner on and off based on steam pressure is the?
Pressure control
If water in the gauge glass is not visible because of failure of feed water supply, what should be done?
Shut off the fuel to the burner and secure the boiler.
What two scales does a pressure control have?
Cut in pressure and differential pressure.
What is the minimum size bottom blowdown line used on a miniature boiler?
1/2”
What is the minimum size drain required on a water column?
3/4”
What conditions are necessary to cause a furnace explosion?
Accumulation of unburned fuel,oxygen and an ignition source.
Low water cut out should be tested:
Daily
Can high pressure safety valve be used on the same boiler for low pressure?
Cannot be used
Gauge pressure + 14.7 psi is called what?
Absolute pressure
The unit that shuts off the burner in the event of low water is?
Low water fuel cut out
The evaporation of 34.5 pounds of water per hour from and at a temperature of 212*F is defined as:
One boiler horsepower
When a safety valve opens and closes rapidly it is referred to as:
Chattering
Furnace explosions are caused by a buildup of combustible gases/ vapors in the combustion chamber. What is the term used to remedy this condition?
Purging
In order for a fuel to burn it must be heated to:
It’s ignition temperature
Why is a pigtail or siphon required in steam pressure gauge lines?
To protect the gauge from a high temperature.
In a steam boiler system, what is the term used for replacing the water that has been lost by blowing down the boiler or through leaks in the system?
Make up water
Heating surface is defined as:
Water on one side / hot gas on the other side.
If a steam trap on a radiator (steam heating system)becomes water logged, what will happen?
The radiator will not heat the room properly.