B1-10 Boiler Maintenance; Types Of Plants and B1-9 Flashcards
A tap drill leaves sufficient material for the tap to produce: A) 60 percent of a full thread B) 75 percent of a full thread C) 80 percent of a full thread D) 90 percent of a full thread E) 100 percent of a full thread
B) 75 percent of a full thread
When drilling a piece of plate steel using a drill press, the piece should be stopped from turning by:
A) securing it with clamps
B) affixing it to the table with contact cement
C) holding it firmly with your hands
D) using locking pliers to hold it
E) bolting a stop to the table
A) securing it with clamps
A threading device stamped with the markings M4-0.7 is used for a thread diameter of: A) one quarter inch B) four inches C) 0.7 centimetres D) 4 millimetres E) 0.7 inches
D) 4 millimetres
Internal threads into which bolts are screwed are cut into a hole using: A) drills B) clippers C) scribers D) taps E) dies
D) taps
A file which has no teeth on the edges is called a: A) 2nd cut file B) dead smooth file C) safe edge file D) pillar file E) flat file
C) safe edge file
In order to check the trueness of a flat surface, the piece should be set up on a: A) hermaphrodite calliper B) surface plate C) vernier calliper D) machinist square E) layout bench
B) surface plate
A common lifting device consisting of an upper and lower set of pulleys connected with a single length of rope is called: A) a come along B) a block and tackle C) a shackle D) a chain block E) a differential pulley block
B) a block and tackle
When raising or lowering an unevenly distributed load, the minimum number of slings required is: A) one B) two C) three D) four E) six
B) two
Whenever two or more sling eyes are used in lifting an object, they should be:
A) fastened with a Crosby clip
B) spaced evenly, regardless of the object’s centre of gravity
C) held in a shackle
D) used only with a come along
E) of equal strength
C) held in a shackle
When an equipment cover is provided with two eye bolts for lifting, the strain must be applied to both the bolts:
A) with exactly the same lifting force
B) using two hoists and a lifting bridle
C) in a vertical direction
D) using a single sling to avoid slippage
E) using two slings from a single crane hook
C) in a vertical direction
One disadvantage of Saran rope is that it:
A) stretches more than other types
B) is not resistant to acids and solvents
C) has low abrasion resistance
D) has a low melting temperature
E) all of the above
D) has a low melting temperature
An eye made in a wire rope using a Crosby clip will have a strength factor of: A) 50% B) 75% C) 80% D) 90% E) 95%
C) 80%
To prevent damage to a work surface while fastening:
A) use toothed lock washers
B) use castle nuts only
C) use a lubricant during threading and tightening
D) use flat washers
E) do not over tighten a nut
D) use flat washers
Machine bolts 8mm in diameter or larger are manufactured: A) only with fine threads B) only with hexagon heads C) with either coarse or fine threads D) only with square heads E) only with coarse threads
C) with either coarse or fine threads
Overheating of boiler tubes may be caused by: 1) excessive firing rates 2) poor water circulation 3) heavy scale formation 4) low water level while firing 5) formation of soot on heating surfaces A) 1,3 and 4 only B) 1,2,3,4 and 5 C) 1,2,3 and 4 only D) 2,3,4 and 5 only E) 1,4 and 5 only
C) 1,2,3 and 4 only
An open water tank should be attached to the vent connection during a wet boiler lay up in order to:
A) prevent water vapour from entering the power plant
B) hold the man way doors closed
C) permit the injection of chemicals
D) prevent air from entering as water volume changes
E) prevent wastage of chemicals
D) prevent air from entering as water volume changes
Cracked tube ends on a fire tube boiler can represent a severe hazard because:
A) the tube may be forced out of the tube sheet by pressure inside the shell
B) the tubes provide structural support to the tube sheets, which is reduced by cracking
C) the cracked ends can cause flue gases to leak into the boiler room
D) cracks concentrate the corrosive effect of the flue gases
E) flue gases will become mixed with the boiler water
B) the tubes provide structural support to the tube sheets, which is reduced by cracking
Before being allowed to weld on a boiler, a welder must have:
A) certain minimum number of years experience
B) performance qualification card
C) welding test conducted
D) certificate of qualification and a performance qualification card
E) certificate of qualification
D) certificate of qualification and a performance qualification card
When laying up a boiler using a wet method, the fire side of the heating surface should be protected from corrosion by:
A) painting with an oil based protective paint
B) placing a desiccant material in the furnace
C) a thin oxide scale that builds up on the surface
D) applying a coat of mineral oil
E) the chemicals in the water used for lay up
D) applying a coat of mineral oil
External boiler inspections can be carried out while the boiler is in service.
A) true
B) false
A) true
Chemical cleaning of smaller boilers is not usually done because:
A) of the thin metal of which they are manufactured
B) the cost to do so is not warranted or justified
C) of the small surface area which the chemical contacts
D) it is impossible to get the chemical circulating adequately
E) they do not have adequate support for the high density of the chemicals
B) the cost to do so is not warranted or justified
A relatively new and safer type of chemical used in boiler cleaning and treatment is: A) chelates B) hydrazine C) sodium hydroxide D) caustic soda E) tri sodium phosphate
A) chelates
In a hot oil system, the oil temperature is controlled by the: A) oil level in heater B) load demand C) firing rate D) air flow E) stack temperature
C) firing rate
Of the following hot oil direct heater types, the one that is most efficient is: A) combination conduction and convection B) conduction C) convection D) combination radiation and convection E) radiant
D) combination radiation and convection
The heaters in a hot oil system should be inspected every: A) 3 months B) 6 months C) 12 months D) 18 months E) 24 months
C) 12 months
The solid formation produced when the oil breaks down as a result of overheating in a hot oil heater is called: A) sludge B) scale C) coke D) residual E) residue
C) coke
The reason for leaving the suction valve on the standby pump of a hot oil system open is to:
A) keep the pump hot and ready for startup
B) prevent air bubbles from forming in the pump
C) prevent contaminants from blocking the suction strainer
D) ensure the safety valve protects the pump from excessive pressure
A) keep the pump hot and ready for startup
The raw material that is used in the largest quantity in the chemical pulping process is:
A) the chemicals used to produce the white liquor
B) water used in the manufacturing process
C) fuel used in the paper mill boilers
D) wood from which the pulp is produced
E) the limestone used to recover liquor chemicals
B) water used in the manufacturing process
In addition to black liquor, most Kraft pulp mills use power boilers which burn primarily: A) natural gas B) waste wood C) bunker oil D) propane E) waste paper
B) waste wood
In a gas processing plant, the liquid hydrocarbons are removed from natural gas by the: A) fuel gas treatment process B) separation process C) stabilization process D) dehydration process E) absorption process
B) separation process
In the recovery boiler furnace, black liquor is burned and:
A) sodium carbonate is converted to sodium hydroxide
B) sodium sulfate is reduced to sodium sulfite
C) calcium carbonate is converted to calcium oxide
D) sodium sulfate is reduced to sodium sulfide
E) calcium oxide is converted to calcium hydroxide
D) sodium sulfate is reduced to sodium sulfide
Production of 1 tonne of Kraft pulp results in the formation of approximately: A) 120 kg of black liquor for firing B) 320 kg of black liquor for firing C) 540 kg of black liquor for firing D) 930 kg of black liquor for firing E) 1300 kg of black liquor for firing
E) 1300 kg of black liquor for firing
In a packing plant, the sides of a carcass of beef are cooled for 24 to 36 hours at approximately: A) 5*C B) 0*C C) -5*C D) -11*C E) -25*C
D) -11*C
The refinery process of breaking down long chain oil molecules into shorter, more valuable molecules (like gasoline) is called: A) vacuum distillation B) centrifugal separation C) hydro-treating D) catalytic cracking E) fractional distillation
D) catalytic cracking