Boiler Flashcards
Where is caustic embrittlement most likely to occur?
on a riveted joint below the water line
The maintenance of automatic direct fired boilers is covered under what document?
ASME CSD-1
What would be the over-speed trip setting on a turbine with a normal operating speed of 1770 rpm?
1947 rpm
How are the tube sheets supported in a fire-tube boiler?
by the shell, stays, and tubes
When making adjustments to the firing rate of a power boiler, why should the air be increased to the burner before the fuel?
to prevent incomplete combustion
On a steam boiler in order to prevent the generation of steam greater than the maximum working pressure requires activation of what device?
The high steam pressure limit control
Is it necessary to provide a disconnect switch at an accessible location at the boiler?
An electrical disconnect switch shall be installed at the boiler at an accessible location with a cover plate that can be locked out in the open position
One mechanical horsepower is equal to:
33,000 ft-lb/min
A boiler with a steaming capacity of 27,117 lbs/hr would be rated at how many boiler horsepower?
786
Who is responsible for obtaining pertinent operating, testing, servicing, and cleaning instructions for the controls and safety devices?
It is the responsibility of the installing contractor to deliver all the instructions to the equipment owner/user
How much heat is required to change 2,500 lb of water to steam at 212 degrees?
2,425,750 Btu
What would occur if there was a drop in the velocity of the liquid flowing through a heat exchanger?
the temperature of the liquid would increase
What chemical should be added to boiler feedwater to prevent oxidation of the boiler drum and tubes?
sodium sulfite
What ASME code symbol is used to denote a high pressure power boiler?
S
The purpose of backseating a manual valve in an operating system is to…
isolate system pressure from the packing stuffing box to minimize packing leakage.
Which of the following stack gas readings would indicate fair to good combustion taking place?
low oxygen and carbon monoxide, high carbon dioxide
What is the horsepower rating of a 10,000 kW steam turbine?
13,400 hp
The Mechanical Inspection Bureau incorporates by reference various codes, standards and practices. Once specific safety practice incorporated by reference for licensed operators specifies and identifies one called a qualified individual. How is the qualified individual identified in this reference?
A boiler service technician who is engaged in and responsible for the installation, replacement, repair or service of the boiler, fuel burning controls, and safety devices and is experienced in such work. In some states this individual must also hold an appropriate boiler operator’s license.
If your boiler needs welded repairs, you must get approval for such repairs from the:
authorized inspection agency
What would one standard atmosphere at 14.7 psi be equivalent to in feet of water?
34 feet
What must take place in order for combustion air to flow open automatically during equipment operation?
There must be an adequate opening for the flow of fuel gas into the confines of the boiler room to ensure proper combustion
What is the total horsepower of a plant that has three 350 hp boilers and one 500 kW steam turbine?
1,720 hp
What water treatment chemical is used to control alkalinity in boiler feedwater?
caustic soda
When a low-water fuel cutoff (LWFCO) has activated on a hot water heating boiler what shall happen?
Operation of the LWFCO shall cause a safety shutdown and lockout, requiring a physical manual reset
In accordance with ASME CSD-1, where is the installation of a manually operated remote shutdown switch or circuit breaker to be located?
Just outside the boiler room door, unless the door is on the building exterior and it must be marked for easy identification and installed on every exit door of the boiler room.
By N.J.A.C. 12:90 rules, what is the minimum thickness allowed for atmospheric type blowdown tank?
5/16 inch
When comparing a globe valve and a gate valve in the same application, the gate valve has a __________pressure drop when fully opened and is the _________choice for throttling.
lower: poorer
If a boiler has an operating pressure of 345 psi and a 2 1/2-inch diameter safety valve, what is the total force acting on the safety valve?
1,693.5 lbs
Which formula would you use to calculate the Btu/lb heat content of fuel oil?
17,687 + 57.7 x API @ 60 degrees F
What is the heating surface of water-tube, with a diameter of 3 1/2 inches and a length of 20 feet?
18.32 sq. ft
In boiler operation what is necessary for complete combustion?
atomization, time, mixture, and temperature
If a power boiler has a burner input of 6,900,000 Btu/hr, what would be its HP rating?
200 HP
Pursuant to N.J.A.C. 12:90, what is the temperature and pressure that defines a high-temperature hot water heating boiler?
250 degrees F at 160 psi
After an adjustment of the packing gland on a valve that had a minor packing leak, the operator attempts to operate the valve but finds it stuck. What is the most probable cause?
The operator overtightened the packing, causing the stem to bind.
Which of the following is a generally accepted method for locally verifying that a manual valve is fully closed in a depressurized static piping system?
Attempt to turn the valve hand wheel in the fully closed direction and verify no movement.
The heat that is added to convert a liquid to a vapor at a constant temperature is called.
latent heat of evaporation
Which one of the following statements is the generally accepted method to verify at the local level that a manual valve is fully closed on a static piping system that is in the depressurized condition?
As an operator you would attempt to turn the handwheel in the closed direction and verify no movement.
What is the purpose of a siphon on a steam pressure gauge?
to protect the gauge from high steam pressure
What is the proper procedure for returning a gauge glass to service, after installing a new glass?
open the drain and crack open the top valve
You are installing a boiler according to the boiler rules and regulations. Where must the filter and strainers for oil fired boilers be installed?
Upstream from the safety shut off valve
When a discharge valve is opened to the atmosphere, the pressure on the upstream side of the valve will…
decrease, and the pressure on the downstream side will remain the same.
In a cooling water system when comparing a 3-inch gate valve to a 3-inch globe valve used for the same application in the process, which statement below is correct if both valves were fully open?
The globe valve produces the larger head loss and the smaller flow rate.
When making adjustments to the firing rate of a power boiler, why should the air be increased to the burner before the fuel?
to prevent incomplete combustion
Furnace explosions can best be avoided by:
purging the furnace after any flame interruption
What must take place in order for combustion air to flow open automatically during equipment operation?
There must be an adequate opening for the flow of fuel gas into the confines of the boiler room to ensure proper combustion
The term viscosity can best be defined as:
the point at which oil starts to flow
In the ignition system on an oil burner, what causes the spark to jump the gap and ignite the fuel?
a high voltage spark of 10,000 VDC produced from the transformer, jumps the gap between the electrode tips.
A gradual increase in the stack temperature could indicate what condition in a boiler?
Select one:
heating surface fouling
What are the three types of draft used in power plants?
natural, forced, and induced
What is the Btu content of natural gas?
100,000 Btu/therm
When the gas limit switch comes into operation, what device does it activate?
fuel line solenoid valve
You are installing a boiler according to the boiler rules and regulations. Where must the filter and strainers for oil fired boilers be installed?
Upstream from the safety shut off valve
Which of the following best defines the term “balanced draft”?
the forced draft and induced draft fans are regulated to keep the furnace below atmospheric pressure
What type of draft system is used to overcome resistance on power boilers equipped with an economizer?
an induced draft system
What are the two element s in fuel oil that produce most of its heat?
carbon and hydrogen
Which of the following stack gas readings would indicate fair to good combustion taking place?
low oxygen and carbon monoxide, high carbon dioxide
Which of the following, best defines the ratio of the total heat supplied by the fuel to the total heat absorbed by the boiler water?
thermal efficiency
The ignition system on a burner must be able to generate enough volts so that it lights the fuel in the burner. What is the line voltage being used?
the line voltage could vary but is typically 120 V AC.
To eliminate the danger of a furnace explosion during start-up, the firing sequence must first allow for:
a pre-purge period
Which formula would you use to calculate the Btu/lb heat content of fuel oil?
17,687 + 57.7 x API @ 60 degrees F
On a rotary cup type burner, the low gas pressure limit switch should be electronically interlocked to the:
the fuel solenoid valve
