問題一覧
1
A low water cut-off usually placed on the boiler from_____to _____ below the NOWL.
2 “ to 6”
2
What is a lantern ring?
Is a spacer installed in between two rings of packing
3
How do you adjust packing?
Tighten one half of a flat on each packing nut at a time alternating from side to side until the leak stops.
4
A_______ is an instrument used to send information about the condition of a process to a control device.
Transmitter
5
Define combined-cycle boiler system?
Is an electric powered generating system that uses both a gas-turbine generator and a steam-turbine driven generator.
6
_______ Is the ability of a material to bend without cracking.
Malleability
7
What is blowdown of a safety valve?
Is the amount of pressure that must be reduced before a safety valve will reseat
8
A______is a chemical that prevent corrosion in condensate and steam pipings.
Anime
9
Should a centrifugal pump be started with the discharge valve open or closed?
Closed
10
______ Is the ability of a material to return to its original shape after being deformed.
Resiliency
11
Water column are made of?
Cast iron, ductile iron, steel
12
What is the last valve to be closed before lighting of?
Economizer vent
13
What happens to the pressure of the discharge side of a centrifugal pump if the pressure from the suction side increases?
Increase in pressure
14
1 sq ft equal how many sq inch’s?
144 sq in
15
_______ Is the ability of a material to withstand pressure before cracking.
Tensile Strength
16
What is cavitation of a pump?
Is when water flashes into steam as it enters the impeller.
17
1 cu ft equals how many cu inches?
1728 cu in
18
Hand holes are typically about_____ in size
4”x5”
19
What type of control operates from steam pressure?
On/Off
20
After blowing down the boiler, the gauge glass slowly returning to normal is an indication of what?
Bottom gauge glass is clogged
21
They say bolt this viscometer is used for_____.
Testing and grading of oil.
22
What prevents leakage around a pump shaft?
Packing
23
_______ is a control in which flow of fuel and air or precisely measured so it is always correctly proportion.
Metering control
24
What refrigerant classification is ammonia?
Type B2
25
A______is the burning of a fuel with precisely the amount of air required so that no unburned fuel or unused oxygen remains.
Stoichiometric Combustion
26
To prevent caking and drying coat entering the pulverizer______.
Warm air is used
27
_____ is exertion of equal forces and opposite direction.
Shear
28
Define cogeneration boiler system?
Is the process of generating electricity then using the leftover heat from the generation process for heating buildings
29
Changing a controlled device to a degree that is proportional to the need is called______.
Modulation
30
What is hard forming scale?
Silica
31
Describe three types of the dearator:
Tray Dearator= Causes water to cascade downward in a zigzag pattern and over small staggered trays. Spray Dearator= Uses self adjusting spray nozzles in the top section to break the water flow into a spray of small water droplets. Combination Tray-Spray Dearator= Uses spray and spray nozzle to break the water flow into a small droplets.
32
Which chemicals is used to combat scale?
Combined phosphate treatment
33
______ Air supply to the furnace to control combustion efficiency?
Secondary air
34
What is desired PH of boiler water?
10.5-11.5
35
What provides circulation to the waterfall tubes?
Down comers tubes
36
How do you adjust a mechanical seal?
There is no adjustment on a mechanical seal
37
What chemical other then sulfite is used to combat corrosion in Boilers?
Hydrazine
38
A_____is an audible alarm that is created electrically or electronically.
Annuciator
39
What are the pressure control on a steam boiler?
Operating pressure cut-out & upper limit control
40
______ results in a high O2 reading?
Incomplete combustion
41
What is a turn down ratio of a modulating burner?
Is the ratio between the maximum firing rate and the minimum firing rate of a burner
42
What are the temp control on a Hot Water boiler?
Operating limit control and upper limit control
43
What is the difference between the safety valve and a relief valve?
Safety valve pops open and reseats when there is measured pressure drop, while relief valve opens in proportion to the excess pressure.
44
_______ result in high carbon dioxide reading in gases of combustion.
Complete combustion
45
The telltale of a stay bolt is usually_____in diameter?
3/16”
46
The slip of a pump typically ranges from_____% to______%
5%-10%
47
What will neutralize acid?
Alkali and lime soda
48
What stamp is put on safety valve after repair?
VR
49
______ Air supply to the furnace to control the rate of combustion.
Primary air
50
Which LWCO does not use mercury switch?
Electronic probe
51
_______ air supply to the furnace when you complete combustion?
Excess air
52
An______ is 1/1000 of an ampere.
Milliamp