"B" Test - 1st Grade Stationary Engineer Flashcards
(158 cards)
1
Q
- How would you change a water glass with a boiler on line?
A
Automatic gauge glass valves will shut, if you don’t have automatic ones close your gauge glass valves, you can operate your boiler with the tri-cocks while replacing the glass. Clean out the broken glass from the fittings, and then crack open lower valve to blow out any other pieces. Then insert new glass and new washers and gaskets back into fittings and tighten nuts. Slowly open top valve first and let the glass expand and heat up evenly, then open bottom valve.
2
Q
- Why are there baffles in the steam drum of water tube boilers?
A
“To stop priming and spouting.
The drum itself is full of baffles or steam separators. These help to prevent water droplets in the steam from accidentally entering the steam header. In other words, the baffles help to prevent a phenomenon known as water hammer and allow for clean dry steam to exit the system.
A wall, barrier, or panel used to change the direction of flow of a liquid or gas. On the waterside of a boiler, baffles may be used to direct the flow of water inside drums or headers. On the fireside of the boiler, baffles may be used to redirect the flow of hot combustion gases through banks of tubes. Fireside baffles are usually made of high temperature refractory material.”
3
Q
- Name three types of superheaters, which is the best and why?
A
“Radiant, Convection, and the Combination type.
Convection, radiant, and combination; combination are best to help maintain uniform steam outlet temps with varying loads.
Convective superheaters (CSH)
Radiant superheater (RSH)
Combined convective and radiant superheaters which are generally pendent type (PSH).
Combination types are best to help maintain a uniform steam outlet temperature. At high fire Radiation type will carry more of the load. At low fire Convection will carry more of the load.”
4
Q
- How much total pressure is on the face of a drum that is 36 inches in diameter with a gauge pressure of 125 psi?
A
“Dia X Dia X .7854 X Pressure = Total lbs. Pressure.
36 X 36 X .7854 X 125 = 127,235 lbs. total pressure.”
5
Q
- What are seven heat losses in a boiler?
A
“Moisture in the fuel, moisture in the air, moisture formed in burning hydrogen, excess air, incomplete combustion, unburned carbon in the ash, radiation.
Moisture contained in fuel.
Moisture in air.
Moisture formed in the burning of hydrogen.
Heat carried away in dry flue gasses.
Incomplete combustion of carbon.
Unburned carbon in ash.
Radiation and other unaccountable losses.”
6
Q
- What is steam tracing?
A
It is used to heat oil lines or to prevent water lines from freezing, it is a small steam line with a trap running beside another line under the insulation.
7
Q
- What is a fusible plug and where is it located?
A
“It is a brass or bronze plug with a tapered hole filled with pure tin, with a melting point of 450ºF. It is a device used to provide protection against low water in the boiler; it is placed at the lowest permissible water level and must extend to make contact with the gasses of combustion.
A temp sensitive device of hollow bronze, filled w/tin solder that causes an audible alarm when exposed to a high temp. Located at the lowest permissible water level and not less than 6 inches above the bottom of the steam and water drum.”
8
Q
- What is inside of a fusible plug and how do you know its melting temp?
A
It is filled with pure tin and melts at 450ºF. The melting temp is stamped on the body.
9
Q
- How do you maintain fusible plugs?
A
“Whenever possible, clean off soot and scale, and replace once a year.
With each outage, examine the plug, clean and scrape to a bright surface of the fusible metal; replace once a year.”
10
Q
- What must be done when the steam gauge is below the header?
A
“For every vertical foot the gauge is below the connection the reading must be corrected by subtracting 0.443 psi from the gauge reading.
Vertical distance / ft. X 0.433 subtracted from Gauge reading = correct pressure.”
11
Q
- How much of the boiler safety valve capacity can be on the superheater?
A
25%, The safety valve on the super heater must be of sufficient capacity to relieve 25% of the steam the boiler can produce.
12
Q
- Which valve must be set to open first, the boiler safety valve or the one on the superheater and why?
A
The super heater safety valve opens first, to prevent a back flow of steam through the super heater and over heating of it’s tubes, which would result if steam was discharged first from the steam drum.
13
Q
- When is it compulsory to have at least two safety valves on a boiler?
A
When heating surface is more than 500 sq.ft. or over 4,000 lbs. per hour steam generating capacity.
14
Q
- How is hardness in boiler water usually measured?
A
Parts per million (ppm) of calcium and magnesium in solution.
15
Q
- What is a sample cooler?
A
A device used to collect a sample of boiler feed water, or condensate return. It cools the water the sample by piping it through a heat exchanger, cooling it prevents evaporation from effecting the test readings.
16
Q
- Give three reasons to save condensate.
A
“Recover boiler chemicals
Recover BTU’s, and
Hot condensate has less oxygen.”
17
Q
- What is the return condensate percentage in the feedwater if the make-up conductivity is 836 mho and feedwater is 172 mho and condensate conductivity is 60 mho?
A
“836 – 172 = 664
836 – 60 = 776
664 / 776 = 85.56%
-172 = 664
-60 = 776
664 / 776 = .85567%
Makeup 836 mho
Condensate 60 mho -> [feed water] —- Feed water 172 mho
{Boiler}”
18
Q
“18. 115. Explain the operation of a thermohydraulic feedwater regulator”
A
It consists of a loop of tubing connected to the water column. Part of the tubing is surrounded by a finned chambers filled with distilled water that does not circulate. This chamber is connected to the diaphragm of the feedwater valve. If the boiler water level drops extra heat is added to the finned chamber, expanding the distilled water that pressure is what opens the feedwater valve.
19
Q
- What need to be done to a new boiler before putting into service?
A
“A hydrostatic test, boil out with alkaline solution to remove the oils and have the safeties checked by a licensed person.
You need to perform a hydrostatic test, have the safety valve checked by a licensed person and boil out with a caustic solution to remove oil.”
20
Q
- When doing a wet lay-up of a boiler how full do you fill the boiler and what chemicals do you add and to what ppm?
A
Fill all the way to the top with deaerated water; add caustic soda to 450 ppm to maintain ph and sodium sulfites (oxygen scavenger) to 250 ppm.
21
Q
- What steps must be taken when performing lock-out tag-out?
A
“1) Notify all person effected by the shutdown.
2) Stop the equipment. Remove all power sources, release any static electricity, pressure, or fluid energy.
3) Apply lock-out tag-out procedures.
4) Check all electrical with a meter and verify that all controls are in the off position.”
22
Q
- What steps must be taken to return locked and tagged equipment to service?
A
“1) Remove all tools, release secured moving parts, and prepare equipment for operation.
2) Make sure affected personnel are clear of the equipment.
3) Replace all safety guards and controls.
4) Remove lock-out tag-out.
5) Energize and test the equipment.”
23
Q
- What are the advantages and disadvantages of injectors?
A
“Advantages: Simple, Compact, No moving parts, Initial cost and installation cost is low, Heats the feedwater and is thermally efficient.
Disadvantages: Inefficient, Easily scaled, is only used on small boilers because it cannot handle high temperatures, unreliable with varying loads.”
24
Q
- The gauge on a pump discharge reads 125 PSI. How high is the discharge pipe?
A
A column of water one foot tall exerts a pressure at its base of .433 PSI so 125/.43=288.68 feet high.
25
25. What is cavitation?
The formation of the vapor bubbles in the suction area of a pump which collapses in the pressure area of the pump resulting in vibration and noise.
26
26. Describe a vertical shaft centrifugal pump and where is it used?
It is a pump with a long enclosed shaft with a volute casing and impeller submerged in liquid being pumped. It may be used in a condensate take, sump pit, swamp, well, etc...
27
27. Why is it important to have good lubrication on centrifugal pumps?
"They operate at high speeds and long periods of time.
handle water that is often at high temps."
28
28. How do you start a steam driven pump?
Open drains on the steam side, open valves on the water side, check lubricators, open pump exhaust valve, open steam valve evenly a little to heat pump, when hot close drains, open steam evenly to start the pump, bring up speed, and recheck lubricators.
29
29. How much horsepower would be required to drive a single acting deep well pump delivering 200 gpm against a measured head of 250 foot?
"200 gpm x 8.33 = 1666 ppm
250 x 1666 = 416500
416500/33000=12.62 hp
GPM X lbs. / gal Xft. of head X specific gravity / Ft. lbs. / Hp. = Hp.
200 X 8.33 X 250 X1.0 / 33,000 = 12.65 hp
GPM lbs./gal ft. of head specific gravity ft. lbs.
Not considering the losses."
30
30. What things do you consider when selecting a new pump?
Type of liquid, Temperature and conditions of liquid being pumped, capacity, variation of suction, total head requirements, space limitations, pump arrangement, the type of drive, ambient conditions and voltage.
31
31. Define wiredrawing.
Wiredrawing is a term applied to the reduction in steam pressure which occurs when steam passes through a throttled valve. This will cut the disk and seat of the valve.
32
32. What is a nozzle and name two types.
A nozzle is a small opening that converts steam pressure into velocity. The two types are divergent and convergent. Con> di<
33
33. How are turbine blades made and of what material are they made? How are the blades fastened and held in place?
"Turbine blades are dropped forged steel, they are rolled and drawn sections of stainless steel.
Rotating blades are secured by “T†root fastenings with lugs machined on the shank straddling the blade groove, and held against the shoulder in the groove by half round sections, caulked in place at the bottom. Stationary blades are anchored in straight sided grooves by a series of short keys, which fit into auxiliary grooves cut in the blade shank, and in the side of the main groove.
They are drop forgings of steel or alloys, depending on the condition under which they are to operate. They are rolled and drawn sections. Rotating blades are fastened in place by a t-root fastening with lugs. Stationary blades are anchored by a series of short keys."
34
34. What is a diaphragm and where is it located?
A diaphragm in an entire assembly of nozzles for one stage of the turbine that is bolted into the steam chest.
35
35. How does an oil relay governor work?
In the oil relay system, the governor operates a small valve, which admits oil to a cylinder with a piston connected by a rod to the steam valve mechanism. The governor admits oil above or below the piston depending on which way the load is changing. The oil pressure is supplied by the lubricating oil pump, loss of the oil pressure shuts off the steam supply, stopping the engine and protecting the turbine bearing.
36
36. Which turbine requires the largest thrust bearing?
Reaction turbines that do not have some method of balancing the force caused by the pressure drop in the rotating blades must be equipped with large thrust bearings.
37
38. How is leaking around the rotor prevented?
With labyrinth packing and water seals.
38
39. How are turbine bearings lubricated and what are the two main qualities needed for turbine lubrication oil?
"Gravity circulation: Oil rings lifting oil to the bearing.
Pressure system: Circulating oil to the bearing.
Two main qualities are correct viscosity and resistance to emulsification."
39
40. How is the viscosity of oil measured?
By a standard say bolt universal (SSU) viscosometer. This test is done by noting the time in seconds it takes 60 ml of oil at standard temps of 70 degrees F, 100 degrees F, 130 degrees F, and 210 degrees F to flow through the orifice.
40
41. Define rupture disk.
A rupture disk is a pre-bulged membrane made of various metals, based on the service for which it is intended. The disk may be used instead of, or with an atmospheric relief valve on the turbine exhaust, in case the condenser looses vacuum.
41
42. What is an air ejector and what is it used for?
"The air ejector draws out the air and vapours which are released from the condensing steam in the condenser. If the air were not removed from the system it could cause corrosion problems in the boiler. Also, air present in the condenser would affect the condensing process and cause a back pressure in the condenser.
A device using a jet of air or steam across a suction chamber into a venture, it is used to prime pumps, remove non-condensables from condensers or draw an initial condenser vacuum when starting a turbine."
42
43. How many gallons per hour will a cooling tower evaporate per ton of refrigeration, knowing that 1000 btus are needed to evaporate 1 pound of water in the tower?
"1000 btus per lb = tower rating; 8.33 pounds per gallon of water; 288000 btus per ton of refrigeration; 1000 x8.33 =8330; 288000/8330 = 34.69 gallons per ton
1 ton of refrigeration = 288,000 BTU’s in a 24 hour period
BTU’s per ton of refrigeration / (rated BTU’s /lb. X lbs./gal)
288,000 (1,000 8.3 = 8,300)
288,000/8,300 = 34.69 gallons per ton."
43
44. Why is superheated steam used in a turbine?
"Superheated steam will do more work, cause less wear, less friction, and less maintenance.
The value of superheated steam in these applications is its ability to release tremendous quantities of internal energy yet remain above the condensation temperature of water vapor; at the pressures at which reaction turbines and reciprocating piston engines operate.
Superheating and pressure reduction through expansion ensures that the steam flow remains as a compressible gas throughout its passage through a turbine or an engine, preventing damage of the internal moving parts."
44
45. What could cause a turbine to be noisy?
Unbalanced rotating parts, misaligned or bent shaft, scale, moisture in the steam, loose bearings, overheating, worn parts, or the sound could be coming from the machine the turbine is operating.
45
46. Name three types of deareators.
"Spray, Tray and combination.
Three specific types, The Spray, Column and the Tray-type."
46
47. If you have a 12†steam line carrying 150 pounds of pressure, what is the total thrust exerted on the fixed anchors?
"150 X 12 X 12 X .7854 = 16,964.64 lbs thrust or 8 ½ ton
Psi X Dia X Dia X .7854"
47
48. List six ways to test steam traps.
Temp difference in and out, listening device, temp crayons, flow indicator, test valves, and knowledge of equipment
48
49. 28.5†of mercury is equal to what psi?
"One inch of mercury is = .491 PSI
.491 X 28.5 = 13.99 PSI"
49
50. How much heat in Btu’s does it take to bring 1 lb. of ice at 20 deg. F to 1# steam?
"Specific heat – amount of heat required to raise the temp of a substance one deg. F.
Latent heat – heat that results in a change of temp.
Sensible heat – heat that can be sensed or measured.
Water – 1 Btu
Ice - .50 Btu
Steam - .48 Btu
12 x .5 = 6 Btu to 32 deg F – water
180 x 1 = 180 Btu to 212 deg. F – boiling water
3 x .48 = 1.44 to 215 deg F – steam (1lb)
Latent heat of ice = 144 Btu per lb
Latent heat of evaporation = 970.3 btu.’s peer lb
6 = sensible heat of ice
970.3 = latent heat of evaporization
1.44 = sensible heat of steam
Answer 1301.74 btu.’s"
50
51. Describe a sling psychrometer and how to use it?
It determines relative humidity. To operate, moisten the wick on the wet bulb and whirl, when the mercury stops dropping, read both thermometers. A comparison of the two temperatures on the psychrometric chart shows relative humidity.
51
52. Draw a psychometric chart? Pg.733
52
53. How would you start a manually operated ammonia compressor?
Open the crossover valve, start and run the compressor for a short period of time, before slowly closing the valve. The idea is not to start the compressor under full load.
53
54. How does a lithium bromide system work?
"There are four main parts in the cycle.
a. generator
b. condenser
c. evaporator
d. absorber
The entire system operates in a near perfect vacuum, using water as a refrigerant and bromide as a absorber.
Heat in the generator section evaporates the water away from the bromide. The bromide flows back to the absorber and the water vapor is condensed in the condenser, then sprayed over the coils in the evaporator, where it again evaporates before being absorbed by the bromide in the absorber section. As the water evaporates it pulls heat from the water or air to be cooled. The bromide/water solution is returned to the generator by a pump which maintains the pressure difference in the system."
54
55. How do you find a leak in a lithium bromide machine?
Remove the lithium bromide and put in a small charge of R-13, and use a leak detector, or helium can be used with a leak detector, or soap bubbles.
55
56. What are advantages and disadvantages of lithium bromide?
"(Advantages) Its non-toxic, non-flammable, non-explosive, and chemically stable substance.
(Disadvantages) When exposed to the air it becomes corrosive, it irritates skin, eyes, and mucous membranes."
56
57. What items would be listed on an EPA refrigerant compliance program check list?
"That the owner/operators of equipment containing over 50 lbs refrigerant:
a. Keep records of refrigerant used and service performed even if a contractor is used.
b. Possess and understand updated regulations and penalties.
c. Have a written mission statement for compliance.
d. A written job description for someone trained in refrigeration.
e. A written policy on detailed record keeping.
f. Copies of EPA certifications for all technicians working on the equipment.
g. A written unintentional venting and leak reporting policy.
h. A written purchasing labeling and handling policy.
i. A written storage and inventory policy.
j. A written leak testing policy.
k. A written policy on disposal of equipment, containers, and lubricates, transporting refrigerants.
l. A response plan for accidents.
m. Documented compliance training on all technicians."
57
57. Explain the N.F.P.A. hazard labeling system.
"The colors and numbers indicate the hazard and the degree of severity
Blue is Health
Red is Fire
Yellow is Reactivity
White is properties and hazards of particular materials.
A number indicates the degree of severity, Highest is 4 hazard down to a 0 hazard."
58
58. What are slip ring motors used for?
"They are used where the starting current of the equipment, starting under full load would be excessive.
Examples are compressors, loaded conveyors, hoists, pumps, mixers, grinders and equipment using large amounts of starting amps."
59
59. What is a three phase ‘Y’ connected alternator?
It has three windings, 120 degrees apart in phase relationship, connected in a Y shape. The middle point of the Y is common connection of one end of each winding. The other end of each winding is a line connection. The middle point of the Y may or may not be brought out as another line connection.
60
60. What is the formula for figuring the efficiency of an electric motor?
"The mechanical energy delivered at the motor shaft divided by the power input of the motor.
It is the output / by the input X 100 = a percentage rating."
61
61. Name and explain the auxiliary device necessary for start-up on a D.C. motor.
A starting rheostat or starting box with considerable resistance is connected in the circuit to reduce the current going to the motor, thus reducing the resistance within the motor as it starts. As it gains speed, the rheostat increases t6he voltage until full speed is attained.
62
62. How do you protect your motors from overloads?
"Fuses and circuit breakers
Overload relays protect the motor, motor branch circuit, and motor branch circuit components from excessive heat from the overload condition."
63
63. How is electricity produced in the generator?
A generator uses a magnetic field created by coils and the electric pressure created in a conductor cutting thought the magnetic field to create voltage.
64
64. What determines the voltage of a D.C. generator?
It depends on the strength of the magnetic field, the number of conductors cutting this field, and the speed of rotation.
65
65. How is a generator protected from a bad ground or short?
"By a circuit breaker, fuses or a ground fault.
Traditional field/rotor circuit ground fault protection schemes employ DC voltage detection. Schemes based on DC principles are subject to security issues during field forcing and other sudden shifts in field current.
To mitigate the security issues of traditional DC-based rotor ground fault protection
schemes, AC injection-based protection may be used. AC injection-based protection ignores the effects of sudden DC current changes in the field/rotor circuits and attendant DC scheme security issues.
95% Stator Ground Fault Protection
3rd harmonic protection implementations are available to complement the 59N element
to provide 100% stator ground fault protection.
Transient ground faults can be detected with the use of an interval timing scheme on the 59G and 27TN protections.
The use of subharmonic injection affords the ability to detect ground faults anywhere in
the stator or in the unit-connected zone regardless of the generator operation and
loading."
66
66. What are phosphates and chelents?
"Internal boiler chemicals used to control hardness in boiler water.
Phosphates are an internal boiler water treatment used to precipitate solids as sludge.
An internal boiler water treatment used to hold solids in suspension."
67
67. What factors determine combustion space of a boiler?
"Needed horsepower, type of fuel to be used
There are several factors that influence the energy performance of boilers including fuel characteristics, firing method, steam pressure, and heating capacity."
68
68. How is factor of evaporation determined?
"The factor of evaporation is the heat added to the water in the actual boiler in Btu per pound divided by 970.3
The heat added by the boiler to convert one pound of water to steam from and at 212 o F / 970.3."
69
69. Where is the feedwater pump in proportion to feedwater heaters?
"The feedwater pump is located between the high and low pressure heaters.
Feedwater heaters can also be ""open"" or ""closed""  heat exchangers. An open heat exchanger is one in which extracted steam is allowed to mix with the feedwater. This kind of heater will normally require a feed pump at both the feed inlet and outlet since the pressure in the heater is between the boiler pressure and the condenser pressure. A deaerator is a special case of the open feedwater heater which is specifically designed to remove non-condensable gases from the feedwater.
Closed feedwater heaters are typically shell and tube heat exchangers where the feedwater passes throughout the tubes and is heated by turbine extraction steam. These do not require separate pumps before and after the heater to boost the feedwater to the pressure of the extracted steam as with an open heater. However, the extracted steam (which is most likely almost fully condensed after heating the feedwater) must then be throttled to the condenser pressure, an isenthalpic process that results in some entropy gain with a slight penalty on overall cycle efficiency."
70
70. What is the difference between a volute and a turbine pump?
"A volute pump is one in which the impeller rotates in a casing of spiral design. A turbine is one in which the impeller is surrounded by diffusion rings.
The primary difference between turbine and volute pumps is the presence or lack of diffusion vanes. In volute pumps there are no diffusion vanes, but rather the outer casing is a spiral. The form of the outer casing reduces water velocity (and eventual pressure) by creating an equal flow of water as it moves around the spiral toward the nozzle. The spiral is sometimes called a volute, hence the name for this particular type of pump."
71
71. Is a centrifugal pump primed running or stopped? Why?
"A centrifugal pump must be primed prior to starting. It cannot pump air.
It is primed while stopped, because it is not a positive displacement pump."
72
72. How does the evaporator condenser work?
An evaporator consists of a steam coil in a tank. Water is fed to the tank; the water boils and leaves the evaporator, where cool condensate runs through coils to condense the vapor, producing distilled water.
73
73. Which requires the largest thrust bearing- impulse or reaction turbines?
Reaction turbines that do not have some method of balancing the force caused by pressure drop in the rotating blades.
74
74. How much horsepower does it take to push 433 lbs of water against a 278 ft head?
433 x 278 x 1 over 33000 = 3.64 hp
75
75. How much horsepower does it take to push 200 gpm against a 250 ft head?
"200 x 8.33 x 250 x 1 over 33000 = 12.62 hp
GPM X lbs. / gal Xft. of head X specific gravity / Ft. lbs. / Hp. = Hp.
200 X 8.33 X 250 X1.0 / 33,000 = 12.65 hp
GPM lbs./gal ft. of head specific gravity ft. lbs.
Not considering the losses."
76
76. How are gasses formed in an ammonia system?
Heat is absorbed in the evaporating coil, which causes the liquid to boil until vaporization is complete.
77
77. Describe how an oil relay governor works.
An oil relay governor is a system whereby the governor operates a small valve in a high pressure oil system, which admits or releases oil to a cylinder and piston which is linked to the stem valve mechanism.
78
78. Explain the water feed regulator on a boiler feed pump.
A feedwater regulator automatically maintains constant and continuous drum level.
79
79. What valves are on the feed line to the boiler?
One feedwater regulator with 2 gate valves and a bypass globe valve, also a check valve.
80
80. Name four kinds of categories of stage turbines.
"Single, velocity, pressure, and pressure and velocity.
Single, velocity, pressure, pressure and velocity, composite.
In modern turbines, three types of staging are employed, either separately or in combination: (1) pressure (or impulse) staging, (2) reaction staging, and (3) velocity-compound staging."
81
81. What is the lowest ph should be on a boiler.
Ph should always be above 10.5.
82
82. How many gallons per hour will a cooling water tower evaporate per ton of refrigeration, knowing that 1000 btus are needed to evaporate 1 pound of water in the tower?
"1000 Btu x 8.33 = 8330 288000 over 8330 = 34.69 gallons per ton.
1 ton of refrigeration = 288,000 BTU’s in a 24 hour period
BTU’s per ton of refrigeration / (rated BTU’s /lb. X lbs./gal)
288,000 (1,000 8.3 = 8,300)
288,000/8,300 = 34.69 gallons per ton."
83
83. What are the temps of oil going to the burner and why should it be near its flash point?
"#4 = 135 degrees #5= 185 degrees #6= 220 degrees It will ignite easier and stay lit."
84
84. How often is it recommended to test your safety valves manually and how often under pressure?
You should test manually once a month and under pressure once a year.
85
85. Explain connecting a safety valve.
"Independent of any other steam connection, close as possible without any unnecessary piping, screwed into the boiler shell or fastened to a flange welded to the shell, connected to stand upright, vents must be fastened to the building and not connected to the valve.
Independent of any other steam connection,
As close as possible to the boiler without any unnecessary piping or fittings,
It shall be screwed or fastened to the boiler shell,
It shall stand upright,
And the vent piping should be securely fastened to the building and not rigidly connected to the valve."
86
86. What is an aspirating pump?
An aspirating pump automatically removes air from the liquid and discharges it to the atmosphere.
87
87. How often do you check the rectifier on an impressed current cathodic protection system?
Every 60 days and keep the records for the readings on file
88
88. Who can inspect and repair your UST leak detection and overfill protection systems and list six things to log on the report?
"A qualified UST inspector/contractor
six things on the report are: Identify equipment, release detection, suspect or confirmed releases, spill and overfill protection, corrosion protection and records kept, walk through inspection."
89
89. Where are msds documents kept?
"They are readily available in the areas of storage
In accordance with individual corporate polices MSDS sheets and records of employee exposure must be kept on file for 30 years."
90
90. Explain the operation of a zeolite water softener.
"Back wash cycle agitates and washes away calcium and magnesium ions as soluble chlorides and the resin beads are coated with sodium ions.
Rinse cycle removes excess of brine from the beads. During use the resin gives up the sodium ions to attract the calcium and magnesium ions."
91
"91. Referring to metal what is tenacity, ductility, malleability, resilience, elasticity, hardness?"
"Tenacity is ability to resist pulling stress.
Ductility is ability to endure elongation.
Malleability is ability to change shape by hammering.
Elasticity is ability to resume normal shape.
Resilience is capacity for storage and return of work energy while being stressed to its elastic limit.
Hardness is ability to resist wear."
92
92. What is a membrane wall on a boiler?
Steel bars welded between the waterwall tubes to seal the combustion chamber.
93
93. What is an accumulation test? When is one needed?
"An accumulation test is a test of the safeties. It is needed after major shutdowns and when bringing up new units.
A test used to determine if the safety valve capacity is large enough to protect the boiler. Shut off the boiler steam outlets and raise the firing rate to a maximum, the safety valves should relieve all the pressure, with out pressure raising more than 6% above set pressure."
94
94. How do you determine the size of a receiver on an ammonia cooling unit for a large company?
The unit must be large enough to contain every thing in the system, including the piping, and allow for 20% expansion.
95
95. What are amines? Name two classes.
Boiler chemicals that evaporate and go out with the steam to keep condensate PH above acid, Low pressure and high pressure Amines.
96
96. Draw the baffling on a three drum sterling boiler.
97
97. Name two wearing rings.
Impeller wearing ring and pump casing wearing ring
98
98 How does a centrifugal pump eliminate balance problems?
"Through the use of balancing devices to control and indicate flow in a return line, thrust bearings, double flow impellers.
balancing the rotating components
they spin at high speeds
?
schedule regular inspections for your pump
Hydraulically and dynamically"
99
99. How do you make PAK-ICE?
"It is made in a congealing tank.
Ice is made using the direct evaporation of ammonia, with jackets forming a cylinder with water inside it. The ice is scraped off the sides as it forms, and is compressed into briquettes."
100
100. Draw a fire safety plan for a boiler.
"A fire safety plan includes the locations of fire alarms, fire extinguishers, the main electrical breaker, fire main, and exits for each area of the facility.
--------------------------------
In the event of a fire, the boiler operator must act quickly to minimize injury and damage. All facilities must have a fire safety plan. A fire safety plan establishes procedures that must be followed if a fire occurs. See Locations of fire alarms, fire extinguishers, the main electrical breaker, the fire main, and exits are listed for each area of the facility. Employee shall have annual fire extinguisher training. Discussion about electrical training for any that would have duty related to the electrical breaker.
https://www.osha.gov/sites/default/files/2018-12/mod_7_boiler_safety2.pptx"
101
101. In an ammonia compression system, how is capacity affected by suction? Discharge? Clearance?
Capacity follows suction, cap high suction high , cap low suction low; capacity is the opposite of discharge, discharge high cap low, discharge low, cap high; the greater the clearance the lower the capacity.
102
102. Where are dashpots located on the turbine? What are they used for?
Dashpot is part of the governor; they stop the governor from hunting.
103
103. How do non-combustibles get into a sealed ammonia line?
Through an air leak in the system.
104
"104. Centrifugal pump delivers 600 gpm and runs at 1,700 rpm, what would be its capacity at 2,000 rpm?"
"New rpm - / old- rpm X gpm = new capacity
2,000 / 1,700 X 600 gpm = 705.9 gpm new capacity
600/1700= .353 .353x2000= 705 gpm"
105
105. How do you regulate the blowdown of a safety valve?
It can be done only by a licensed person; they would adjust the blow back ring, the spring tension or both about 10% for pressures up to 250 psi.
106
106. When doing a wet lay up of a boiler, how full do you fill it and what chemicals do you add to what ppm?
Fill all the way to the top with deaerated water; add caustic soda to 450 ppm to maintain ph and sodium sulfites (oxygen scavenger) to 250 ppm.
107
107. What are the advantages and disadvantages of injectors?
"Advantages: simple, compact, no moving parts, initial cost and installation is low, heats the feedwater and is thermally efficient.
Disadvantages: inefficient, easily scaled, is only used on small boilers because it cannot handle high temperatures, unreliable with varying loads"
108
108. List 5 things daily that you would check in a cooling tower.
"Conductivity,
PH,
Algae (ORP),
Water level,
Noise and
Vibration.
Corrosion of internal structures
Water Quality Issues
Mechanical damage of moving parts
traces of heterotrophic bacteria
clarity of sump water
inspect the basin flow control valves
check the float ball and make-up valve
lubricate the motor bearing"
109
109. How do you keep a cooling tower from freezing when not on service?
You could run the pump and by-pass all the water to the basin, or drain the basin and makeup lines.
110
110. Why would you have a vacuum breaker on a turbine?
The over speed trip closes the throttle and operates the vacuum breaker to eliminate over speeding and it is to prevent damage to the turbine if the condenser became flooded.
111
"111. Which is more critical on the boiler, the temperature or the pressure and why?"
The temperature, because steam can be superheated beyond boiler design.
112
112. What are two reasons for a chimney?
To create a draft, and to remove products of combustion.
113
113. How do you relieve stress on a boiler weld?
After boiler construction or repair, the boiler drum is heated to about 1,150ºF for one hour per 1†inch of thickness and slowly cooled.
114
114. Who is authorized to handle refrigerant?
You must be certified to remove or add refrigerant to the system.
115
115. What spill protection is required on fuel tanks?
"That there must be catchment basin with a fill opening with a capacity of 5 to 25 gallons.
A containment sump which can hold the contents of the tank plus some. There must be a catch basin around the fill opening with a capacity of 5-25 gallons. "
116
116. List three overflow protections required on a fuel oil tank.
Automatic shut off devices on the fill, overfill and high level – audible alarms, ball float valves on the vent.
117
117. How much oil can be spilled before you call the EPA?
25 gallons
118
118. The EPA requires what records are kept regarding underground fuel tanks?
Upon request you must provide to EPA records on installation, monitoring, cathodic protection, release detection equipment calibration, maintenance repairs and closures.
119
119. What does msds stand for and what is its purpose?
Material safety data sheets include the chemical properties, hazards, antidotes, and firefighting requirement of possible hazardous materials.
120
120. What is a confined space?
It is a space large enough to physically enter and exit and is not designed for continued occupancy.
121
121. Excluding polyphase motors, what is the standard rotation for motors and generators?
Standard rotation of motors is counter clock-wise and for generators it is clockwise when viewed from the front of the machine.
122
122. What makes a safety valve pop?
"The huddling chamber increases the total force on the disk surface as the valve lifts.
The huddling chamber increases the total force on the disk surface as the valve lifts, or the safety valve has the disk held on its seat by a spring which can be adjusted to give variation in popping pressure, this is accomplished by the compression screw which forces the valve against its seat."
123
123. Explain the purpose for injectors.
"An injector is a system of ducting and nozzles used to direct the flow of a high-pressure fluid in such a way that a lower pressure fluid is entrained in the jet and carried through a duct to a region of higher pressure. It is a fluid-dynamic pump with no moving parts except a valve to control inlet flow. A steam injector is a typical application of the principle used to deliver cold water to a boiler against its own pressure, using its own live or exhaust steam, replacing any mechanical pump.
To prime pumps, remove non-condensables or draw an initial condenser vacuum when starting a turbine.
• To inject chemicals into the boiler drums of small, stationary, low pressure boilers. In large, high-pressure modern
boilers, usage of injectors for chemical dosing is not possible due to their limited outlet pressures.
• In thermal power stations, they are used for the removal of the boiler bottom ash, the removal of fly ash from the
hoppers of the electrostatic precipitators used to remove that ash from the boiler flue gas, and for creating a
vacuum pressure in steam turbine exhaust condensers.
• Jet pumps have been used in boiling water nuclear reactors to circulate the coolant fluid.[4]
• For use in producing a vacuum pressure in steam jet cooling systems."
124
124. What is the purpose for a water leg on a Heine boiler?
It circulates water to the steam drum and it holds the tubes and supports the boiler.
125
125. Name two types of coal pulverizers.
"Roller mill and ball mill
Contact Mill,
Ball Mill,
Impact Mill.
Impact – an external force impacts with the coal. This type of grinding can be compared to when a hammer hits an object e.g. a piece of coal.
Coal is fed into a rotating cylinder containing steel balls of around 50 mm diameter. When the cylinder rotates, the balls rotate along with the cylinder and fall down when they reach the top position. Coal is ground due to attrition and impact.
Crush – the coal is forced between two bodies. This type of grinding has the same effect as a rolling pin when rolling across salt granules on a table.
This type consists of a rotating shaft inside a stationary cylinder . The shaft contains arms that impact the coal inside the cylinder. The impact powders the coal. The hot air carries the coal to the burners.
Attrition – the coal is ground against itself. Rubbing two sugar cubes against themselves represents attrition grinding.
Coal feeds onto a steel rotating table. Tapered, cylindrical, or spherical rollers on top of the table, under spring pressure, exert force on the coal particles on the table. When the table rotates, the coal passes between the rollers and the table and gets ground due to attrition. The hot air under pressure carries this ground coal upwards. Larger particles fall back to the grinding table. These coal particles then pass through a classifier where the large particles get separated due to centrifugal action and are returned back to the grinding table."
126
126. What is caulking on a boiler and what if it fails?
"A riveted joint inside the drum is caulked by using a blunt tipped chisel to drive the metal of the joint tight against the drum; it prevents boiler water from entering the joint and deteriorating it.
Riveted joints are made tight by driving the inside edge of the strap against the shell using a blunt chisel. If the caulking fails, water will become concentrated in the joint and the metal will crack."
127
127. Describe gland sealing steam.
It is low pressure steam, used in conjunction with labyrinth packing to seal the low pressure end of the condenser.
128
128. How would you find a leaking tube in a shell heat exchanger?
Remove heads, and put pressure on the tubes and look for leaks, or use a listening device.
129
129. The gauge on a pump discharge reads 125 psi, how high is the discharge pipe?
A column of water exerts a pressure at its base of .433 psi, so 125/.433=288.68 feet high.
130
130. What are the advantages and disadvantages of fuel oil versus coal?
"Advantages over coal, it is easily stored, less space, safer, less man power needed, cleaner emissions, plant can be kept clean.
Disadvantages - cost of oil higher, impurities plugging strainers and burners, cleaning of tanks and disposal of sludge costly, sulfur in oil causes corrosion in equipment and pollution of air."
131
131. Draw two boilers using one feedwater pump.
132
132. Name two types of evaporators.
In refrigeration you have Dry (droplet) type and the Flooded type.
133
133. What is a polisher?
A polisher is an ion exchange process which is used to remove trace contaminants both dissolved and suspended from high purity water.
134
134. What is a demineralizer?
"A demineralizer removes practically all dissolved solids in water.
352. What is demineralization?
An ion exchange process using strong acids and bases, in the regeneration used for high-pressure boilers."
135
135. What is the function of a boiler evaporator?
This produces distilled water with minimum heat loss.
136
"136. Why is octyl alcohol added to a chiller?"
"Octyl alcohol reduces surface tension in the absorber.
The alcohol is used to provide better heat transfer in
the absorber"
137
137. Name 5 EPA responsibilities.
"EPA is a federal agency set up to control and abate pollution in the areas of air, water, waste, solids, pesticides, radiations, and toxic substances.
Establish and Enforce Regulations.
Offer Grants.
Study Issues Affecting the Environment.
Teach Others About the Environment.
Assist in Homeland Security."
138
"138. What is meant by total head on a pump?"
"The total head on a pump is the sum of the velocity-head, the total friction head, and the total measured head.
The difference in height between the level of liquid in the suction tank, and the height of a column of water that the pump can achieve.
Total Head = Pump Head – Suction Head
It is figured by total static head of discharge above the level of suction water pressure at the point of discharge, and pipe fiction including fittings.
Total head is the net difference between the suction and discharge heads."
139
"139. Describe the water circulation of a Stirling boiler."
Feedwater enters the economizer, then enters the top drum, and flows down the rear bank of tubes to the lower drum. Steam generated in the first two banks of boiler tubes returns to the right and center drums, finally all the steam generated in the boiler and waterwall reaches the left hand drum, then head to the superheater and out to the main steam line.
140
"140. How are adjustments of 2-3% made on the turbine governor?"
By adjusting the tension on the spring or the weight of the fly balls.
141
"141. What is a water seal used for?"
"It is used around the turbine shaft at the high pressure end of the turbine.
A water seal consist of a centrifugal pump runner attached to the turbine shaft. The runner rotates in a chamber, in the gland casing. Water is supplied to the chamber at 3 to 8 psi and is thrown out against the sides by the runner, forming a seal. They are used on the low pressure end of a condensing turbine."
142
"142. Draw a psychometric chart."
143
A safety valve with a 3†seat is on a boiler operating at 100 psi, what is the total pressure acting on the valve?
"Total Force = A X P
TF = 0.7854 X D sq. X P
0.7854 X 3 X 3 X 100 psi = 706.86 lbs. Total Pressure"
144
What do you consider the most important step in the care and maintenance of a steam turbine?
"The yearly inspection.
Steam turbine bearings and seals should be physically inspected every two to three years. This entails opening the bearing housings; removing and inspecting the bearings and seals; and replacing any components as needed. The work is generally done during a planned shutdown."
145
What is the pressure stage, velocity staging and what is the difference?
Pressure stage allows only a limited pressure drop in one set of nozzles. Velocity staging is applying velocity energy in the steam coming from the nozzles to two or more sets of moving blades, with the pressure drop occurring in the stationary blades. The difference is where the pressure drops occur.
146
What is the difference between an impulse and a reaction turbine, name four types?
"The impulse turbine is designed so the expansion of the steam occurs almost entirely in its stationary blades, and there is almost no pressure difference of the steam entering and leaving the stages.
Types of Impulse: Re-entry flow, rotor, vertical, horizontal, de Laval Wilkinson, Zoelly, Pelton.
The reaction turbine is designed so there is considerable expansion in the rotating blades and there is a pressure difference of the steam entering and leaving the stages.
Types of Reaction: Tamden, Cross compound, single flow, double flow, Parsons, Allis chambers, Ingersal Rand."
147
What is the purpose of the shaft sleeve?
"To protect the shaft from corrosion and damage from grit.
A shaft sleeve acts as a shield for the shaft assembly in pumps and compressors. A shaft sleeve is a hollow metal tube, cylindrical in shape, which is mounted over a shaft and shaft assembly to protect it in a corrosive environment.
Shaft sleeves are commonly found in single stage pumps. The pump shaft usually offers protection from corrosion and erosion."
148
How would you identify leaking coil in a closed water heater?
"Two ways:
If designed for this, flood the shell side of the condenser and check for water running or dribbling out of the heat exchanger tubes.
Or - use helium leak detection to check for very small leaks like MIC attack. It is expensive but it will find even the smallest of leaks in heat exchanger tubes.
When checking for leakes, we took both heads off the condenser (a two pass shell/tube exchanger) and filled the shell side with water and pressured it up to 80 psig. Then we dried the tubes as much as we could by blowing them with high pressure nitrogen, each tube individually. We then waited for 30 minutes and then blew the tubes out again, no water came out of any of them.
eddy current testing on heat exchanger tubes to look for corrosion
pressure drop, ultrasonic, helium"
149
What should the temperature of water be leaving the DA?
"Under design conditions the temperature of the outlet water approaches the saturation temperature of the supply steam.
The temperature of the feedwater tank should be maintained between 185 and 195°F (85 and 90°C) to reduce the amount of oxygen in the water. By increasing the temperature and reducing the oxygen content, you can greatly reduce your sulfite or oxygen scavenger requirements.
a temperature of 225 to 227 degrees"
150
239. What is considered a perfect vacuum?
29.92†of mercury.
151
404. Chief difference in design between a condensing and non-condensing high pressure turbine?
The difference between a condensing and non-condensing turbine is that a condensing turbine exhausts to some type of condenser which condenses the steam back to water for re-use in the system. This also causes the low pressure end of the turbine to be operating under a vacuum. A non-condensing turbine, sometimes called a backpressure turbine exhausts to atmosphere. The low pressure end of a non-condensing turbines will be at atmospheric pressure and above.
152
Cathodic rectifier tested how often? What does the test consist of? What happens if the test fails?
"Periodic testing is required for each type of system as follows:
· Sacrificial anode: Every three years
· Impressed current: Every year
In addition to annual testing, the rectifier of an impressed current CP system must be checked every two months to ensure that current is being delivered to the system. Document this in writing by recording the date, the voltage and amperage displayed on the gauges, and the initials of the person reading the gauges. If the rectifier has an hour meter, record the hours as well. Rectifier readings of impressed current CP systems may be taken by the owner or another person.
Advance notification to the MPCA of CP testing is not required. The CP tester must evaluate the CP system according to NACE RP0285, “Corrosion Control of Underground Storage Tank Systems by Cathodic Protection.â€
At least three test points per tank and per piping run must be utilized. Of the three test points, one must be a local test point, and one must be a remote test point. The third test point can be either local or remote.
In order to pass, a sacrificial anode CP system must show structure-to-soil potentials of at least -850 mV for all metal system components. For an impressed current CP system to pass, all components must meet the -850 mV
(Instant Off) criteria. In the alternative, the difference between the depolarization voltage and the Instant Off voltage must be at least 100 mV. If one or more components do not show this level of structure-to-soil potential, the system fails and must be repaired or replaced.
Structure continuity testing must also be performed. For sacrificial anode CP systems, the continuity tests must demonstrate each protected structures (tank or pipe) are electrically isolated from other protected structures and non-protected structures (electrical conduits, risers, vent lines). For impressed current systems, continuity tests must demonstrate all protected structures are electrically continuous with each other.
One common repair is to add new anodes or replace old ones. Repairs must be completed within 60 days after a failing test or as otherwise required by an MPCA enforcement action.
Sacrificial anode or impressed current systems may be repaired by a CP tester who is qualified to repair CP systems according to industry standards, or by a corrosion expert.
The system must be re-tested within six months after any repairs. Cathodic protection test results must be submitted to the MPCA within 30 days of testing
https://www.pca.state.mn.us/sites/default/files/t-u3-27.pdf"
153
309. How often do you check a rectifier on a fuel tank? Who can check it? What do you check?
You must inspect it every 60 days and keep records of three readings on file. A qualified cathodic protection inspector would check the D.C. output. If testing a rectifier, it must be done after six months of installation and every 3 years after.
154
188. What is the lowest flash point for oil used in a turbine?
325ºF
155
What type of oil is used in turbine?
"A very high grade mineral oil which seaparates readily from water, flash point which is not below 325 F.
• Shed water that allows solid particles to settle where they can be removed through drains or filtration systems during operations
• High operating temperature
• Ability to release water and hydrolytic stability
• Antifoaming when in contact with air
• Wear protection of gearbox, shaft"
156
Types of deaerators:
"Tray – domed dearation mounted top of horizontal storage, feedwater enters above trays and flows downward, low pressure steam enters trays and flows upward, steam and feedwater mixes strips the gas from feedwater, gas exits at vent on top of dome section. Dearated water flows downward where it is pumped to the boiler.
Spray – Horizontal vessel has preheating section and dearation section separated by baffle, low pressure steam enters vessel through sparger at bottom of vessel. Preheater section heats feedwater to help remove dissolved gases, preheated feedwater flows into deration section, gas stripped from water exit at the vent, feedwater is pumped at the bottom of vessel.
Packed column type – Water enters through spray valves directed downward into steam atmosphere in first stage where water is heated within 2 degrees of steam temperature. Preheated water containing dissolved gasses flow into second stage packed column. Water flows down through packing being in contact with fresh gas free steam. Steam enters the base of the column and mixes with the preheated water. Contact with the steam releases the dissolved gasses. Little steam is condensed because its temperature is close to the preheated water. The steam after passing the column continues upward into the vent and spray valves where it is condensed, leaving the non-condensable gasses to escape to the vent."
157
43. What is a 3 phase alternator?
A three phase alternator is an AC electrical generator with 3 sets of windings in the stator. These windings overlap each other in a phase angle, or timing relationship, by 120 degrees with respect to each other. The rotor (field or excitation) current is DC, and adjusted to regulate the output power.
158
140. What is meant by boiler encrustation?
Scaling of the heating surfaces.
