Steam Flashcards
Why is superheated steam used in the main propulsion turbines instead of saturated steam?
(a) Less specific energy available per pound of steam.
(b) Greater heat energy available per pound of steam.
(c) Higher pressure available than saturated steam.
(d) Lower required specific volume than saturated steam.
(b) Greater heat energy available per pound of steam.
As steam accomplishes work in an engine or turbine, the pressure of the steam is reduced because it __________.
(a) becomes saturated again
(b) diminishes in volume
(c) expands in volume
(d) becomes superheated again
(c) expands in volume
The device illustrated is referred to as a/an \_\_\_\_\_\_\_\_\_\_ . GS-0048 A inverted bucket trap B upright bucket trap C "P" type trap D none of the above
A inverted bucket trap
The function of the device illustrated is to __________ . GS-0048
A control steam input to a heat exchanger
B control condensate output from a heat exchanger
C provide on/off control of drain pump
D provide air purging of low pressure refrigeration or air conditioning systems
B control condensate output from a heat exchanger
The trap illustrated operates as a __________ . GS-0005
A thermostatic bellows type steam trap
B thermodynamic bellows type steam trap
C thermostatic bi-metalic bellows type steam trap
D thermodynamic float type steam trap type steam trap
A thermostatic bellows type steam trap
The quantity of condensate passing through the illustrated steam trap will be reduced as the __________ . GS-0005
A amount of vapor contained in “A” decreases
B amount of liquid contained in “A” increases
C amount of vapor pressure contained in “A” increases
D vapor pressure of the liquid contained in “A” decreases
C amount of vapor pressure contained in “A” increases
[“A” will expand, pushing “C” closer into “D,” restricting flow of condensate.]
What statement representing the primary purpose of a steam trap is true?
(a) By draining the low point of a horizontal run of steam piping, a steam trap is used primarily to keep the steam line dry and eliminate water hammer.
(b) By draining the high point of a horizontal run of steam piping, a steam trap is used primarily to keep the steam line dry and eliminate water hammer.
(c) By draining the high point of a vertical run of steam piping, a steam trap is used primarily to keep the steam line dry and eliminate water hammer.
(d) By draining the low point of a horizontal run of steam piping, a steam trap is used primarily to insure good heat transfer efficiency.
(a) By draining the low point of a horizontal run of steam piping, a steam trap is used primarily to keep the steam line dry and eliminate water hammer.
In order for a steam trap to be effective in accomplishing its intended purpose, what statement is true regarding its installation?
(a) The steam trap should never be painted, but should be covered with insulation.
(b) The steam trap should be painted to reduce corrosion and should be covered with insulation.
(c) The steam trap should be painted to reduce corrosion but should never be covered with
insulation.
(d) The steam trap should never be painted and should never be covered with insulation.
(d) The steam trap should never be painted and should never be covered with insulation.
The most critical period of main turbine operation is during cold start-up, rather than hot shutdown because __________.
(a) harmonic vibrations associated with critical speed can easily be reached during start-up
(b) the danger of blade erosion damage from dry steam impingement is greater during start-up
(c) lubricant film thickness during start-up is considerably less than the dimensions of gear
surface irregularities
(d) differential expansion can result from the temperature difference between the rotor and rotor casing
(d) differential expansion can result from the temperature difference between the rotor and rotor casing
If “E” is moved closer to the top of “B” as shown in the illustration, the __________ . GS-0002
A efficiency of the heat exchanger operation will be increased
B point of condensation will be moved closer to the steam inlet of the heat exchanger
C point of condensation will be moved closer to the condensate outlet of the heat exchanger
D steam pressure set point will automatically be increased
B point of condensation will be moved closer to the steam inlet of the heat exchanger
Referring to the illustrated bellows-type thermostatic steam trap, what statement is true concerning its operation? GS-0005
A When the bellows comes into contact with relatively cool condensate, the vapor within the bellows condenses resulting in bellows contraction and valve opening.
B When the bellows comes into contact with relatively hot steam, the vapor within the bellows condenses resulting in bellows contraction and valve opening.
C When the bellows comes into contact with relatively cool condensate, the liquid within the bellows vaporizes resulting in bellows expansion and valve closing.
D When the bellows comes into contact with relatively hot steam, the liquid within the bellows vaporizes resulting in bellows contraction and valve opening.
A When the bellows comes into contact with relatively cool condensate, the vapor within the bellows condenses resulting in bellows contraction and valve opening.
Which of the listed types of steam traps operates on the principle that hot water flashes to steam when its vapor pressure is rapidly reduced? A Ball float B Thermostatic C Bimetallic D Impulse
D Impulse
The gravity tank in a gravity lube oil system serves to __________.
(a) settle lube oil prior to purifying
(b) maintain oil supply for several minutes to bearings should the lube oil service pump fail
(c) store heated lube oil
(d) supply the lube oil service pump with a positive suction head
(b) maintain oil supply for several minutes to bearings should the lube oil service pump fail
Which of the following conditions is indicated by oil flowing through a lube oil gravity tank overflow sight glass?
(a) Turbine bearing failure has occurred.
(b) Insufficient oil is being pumped to the gravity tank.
(c) Excessive oil is stored in the gravity tank.
(d) Sufficient oil flow is being supplied to the gravity tank.
(d) Sufficient oil flow is being supplied to the gravity tank.
Bottom blow valves are installed on auxiliary water-tube boilers to __________.
(a) completely drain the boiler in an emergency
(b) prevent sludge from forming in the steam drum
(c) remove floating impurities from the boiler water surface
(d) remove settled solids from the water drum
(d) remove settled solids from the water drum
