126-250 Flashcards
- Name one characteristic feature of mechanical steam traps.
a) They pass condensate at steam temperature
b) They operate by sensing condensatet emperature
c) They can be fitted into any position
d) They are not affected by increasing back pressure
a) They pass condensate at steam temperature
- In a mechanical steam trap, why is a float trap better at venting air than an inverted bucket trap?
a) A float can quickly adjust to the presence of air
b) A float is fitted with an automatic air vent
c) A float trap does not vent air better than bucket trap
d) The air vent orifice is adjustable on a float trap
b) A float is fitted with an automatic air vent
- A heat exchanger is designed to operate without waterlogging of the steam space. What is the usual choice of trap for its drainage?
a) Thermostatic trap
b) Inverted bucket trap
c) Thermodynamic trap
d) Float trap with thermostatic air vent
d) Float trap with thermostatic air vent
- In a mechanical steam trap, what advantage does a bucket trap have over a float type?
a) It is able to withstand water hammer
b) It can be used on higher pressure
c) It can discharge air freely
d) It cannot lose its water seal
b) It can be used on higher pressure
- In a mechanical steam trap, what added benefit does the automatic air vent offer to a float trap?
a) It stops the trap from freezing in cold weather
b) The trap can be use on larger backpressures
c) It significantly increases the cold start-up capacity of the trap
d) The condensate orifice can be the same size for all pressure gauges
c) It significantly increases the cold start-up capacity of the trap
- Which is the best trap to use when steam locking can occur?
a) An inverted bucket trap with an internal check valve mechanism
b) A balanced pressure steam trap
c) A float trap with automatic air vent
d) A float trap with steam lock release mechanism
a) An inverted bucket trap with an internal check valve mechanism
- What is a common cause of water-hammer in drying coils?
a) Wet steam supplied to the coil
b) Too low a steam pressure onto the coil
c) Condensate has to lift after the steam trap
d) The coil falling in the direction of steam flow
c) Condensate has to lift after the steam trap
- Which of the following statements is true?
a) Bimetallic steam traps are an ideal choice for rotating cylinders
b) Rotating cylinders cannot suffer from steam locking
c) Strainers cannot be fitted to float traps which have a steam lock release
d) Air vents around the thermodynamic and inverted bucket traps can considerably improve start-up times
d) Air vents around the thermodynamic and inverted bucket traps can considerably improve start-up times
- Name the principal cause of water-hammer?
a) Water particles suspended in steam
b) Water allowed to build up in pipes
c) Water droplets carried along the insides of pipes
d) Wet steam passing through steam traps
b) Water allowed to build up in pipes
- What do you call a boiler of which both the location and ownership have been change after primary use?
a) Second hand boiler
b) Surplus boiler
c) Miniature boiler
d) Reinstalled boiler
a) Second hand boiler
- What effect does steam locking have on rotating machinery?
a) None at all
b) It reduces the drying rate of drying cylinders
c) It increases the drying rate of drying cylinders
d) It causes the steam trap to air bind
b) It reduces the drying rate of drying cylinders
- It is a boiler removed from its original setting and re-erected at the same location, or erected at a location without change of ownership. How do you call this boiler?
a) Second hand boiler
b) Surplus boiler
c) Miniature boiler
d) Reinstalled boiler
d) Reinstalled boiler
- Each miniature boiler shall be equipped with which of the following for the determination of water level?
a) Safety valve
b) Fusible plug
c) Water gage glass
d) Pressure gages
c) Water gage glass
- The maximum allowable working pressure of a non-code steel or wrought iron heating boiler of welded construction shall not exceed to which of the following pressures?
a) 1 atmosphere
b) 1 Bar
c) 100 kPa
d) 2 gage pressures
b) 1 Bar
- What do you call a refrigeration system in which the refrigerant gas evolved in the evaporator is taken up in an absorber and released in a generator upon the application of heat?
a) Absorption refrigeration system
b) Cascade refrigeration system
c) Flooded refrigeration system
d) Steam jet refrigeration system
a) Absorption refrigeration system
- What do you call a shut-off valve other than a valve for controlling the flow of refrigerant in a refrigeration system?
a) Fusible valve
b) Stop valve
c) Check valve
d) Relief valve
b) Stop valve
- What is a device, used in refrigeration system, having a predetermined temperature fusible member for the relief of pressures?
a) Fusible valve
b) Stop valve
c) Check valve
d) Relief valve
a) Fusible valve
- It is a measure of the lack of potential or quality of energy; and once that energy has been exchanged or converted, it cannot revert back to a higher level. What is this?
a) Specifc heat
b) Entropy
c) Internal energy
d) Molecular energy
b) Entropy
- What do you call the method used to evaluate all welds performed on pressure parts of boiler tube materials?
a) Radiographic test
b) Hydrostatic test
c) Vacuum test
d) Orsat analysis
a) Radiographic test
- What do you call a form of boiler fuel that is easy to burn, with very little excess air?
a) Coal
b) Oil
c) Gas
d) Bunker
c) Gas
- It is a boiler testing method that is used to verify the microstructure of the boiler tubes using optical microscopes. How do you call this method?
a) Tube sampling
b) Metallurgic replication
c) Radiographic testing
d) Optical testing
b) Metallurgic replication
- Which of the following is true regarding the relation of rk and re for spark-ignition engine, where rk = compression ratio while re = expansion ratio?
a) rk > re
b) rk < re
c) rk = re
d) re is not considered in the spark-ignition engine
c) rk = re
- It is the generic term given to a family of solid fuels with high carbon content. How do you call this?
a) Solid fuel
b) Coal
c) Anthracite
d) Bituminous
b) Coal
- It is a boiler fuel created from the residue produced from crude petroleum after it has been distilled to produce lighter oils like gasoline, paraffin, kerosene, diesel or gas oil. What is this fuel?
a) Oil
b) Kerosene
c) Coke
d) Peat
a) Oil
- The second law of thermodynamics says that whenever energy is exchanged or converted from one form to another, the potential for energy to do work will be
a) Decreased
b) Increased
c) Zero
d) Stagnant
a) Decreased
- What is true about steam as it condenses?
a) It does so at constant entropy and temperature
b) It does so at constant enthalpy and reducing temperature
c) Both enthalpy and entropy reduce and temperature remains constant
d) Both enthalpy and entropy increase
c) Both enthalpy and entropy reduce and temperature remains constant
- It is an increase in fluid pressure in a long pipe caused by a sudden velocity decrease, where the sudden decrease in velocity is caused by a valve closing.
a) Aero dynamics
b) Water hammer
c) Terminal velocity
d) Drag
b) Water hammer
128.It is an upward force that is exerted on an object (like flat plate, airfoil, rotating cylinder, etc.) as the object passes through a fluid. What do you call this?
a) Drag
b) Lift
c) Aero horsepower
d) Terminal velocity
b) Lift
- What is a frictional force that acts parallel but opposite to the direction of motion of fluid?
a) Drag
b) lift
c) Aero horsepower
d) Terminal velocity
a) Drag
- It is a term used by automobile manufacturers to designate the power required to move a car horizontally at 50 mi/hr against the drag force. What is this?
a) Mechanical horsepower
b) Aero horsepower
c) Fuel power
d) Fluid power
b) Aero horsepower
131.A manufacturer claims that it has a COP of 2.0 when cooling a food at 5 oC using ambient air at 30 oC as a heat sink. Is the claim of the manufacturer valid?
a) Yes
b) No
c) Probably
d) It needs experimental verification
a) Yes
Note: Yes, because the claimed COP of the manufacturer is lower than the COP of Carnot Refrigeration
- What can you say about the velocity of fluid at the center of the pipe section?
a) Maximum
b) Minimum
c) Average
d) Zero
a) Maximum
- Continuity equation is applicable to which of the following?
a) Viscous and unviscous fluids
b) Compressibility fluids
c) Conservation of mass
d) Steady and unsteady flows
c) Conservation of mass
- Hygrometer is an instrument used to determine of which of the following?
a) Specific gravity of fluids
b) Specific gravity of gases
c) Specific gravity of liquids
d) Specific gravity of solids
a) Specific gravity of fluids
- At critical point of a pure substance, what is the value of latent heat?
a) Maximum
b) Minimum
c) Zero
d) Below zero
c) Zero
note: Zero, at the critical point hg-hf=0
- Which of the following is a function of a steam nozzle?
a) Converts kinetic energy into heat energy
b) Changes internal energy into kinetic energy
c) Converts potential energy into heat energy
d) Changes enthalpic energy into kinetic
energy
d) Changes enthalpic energy into kinetic
energy
- Generally, steam turbines in power station operate at which of the following speeds?
a) 3000 rpm
b) 1000 rpm
c) 4000 rpm
d) 500 rpm
c) 4000 rpm
- Tidal power is the power generated from which of the following?
a) Waves of the ocean
b) Thermal energy of ocean water
c) Raw sea water
d) Rise and fall of tides
d) Rise and fall of tides
- Which of the following is an expression or equivalent of? horsepower per ton of refrigeration?
a) COP/ 4.715
b) 4.715/COP
c) COP x 4.715
d) 1/ (4.715 x COP)
b) 4.715/COP
140.It is the ratio of the amount of heat taken up by a substance to the temperature at which the substance exists. How do you call this?
a) Internal energy
b) Flow energy
c) Enthalpy
d) Entropy
d) Entropy
- Which of the following is a type of water turbine where a jet of water is made to fall on the blades or buckets and due to the impulse of water the turbine starts moving?
a) Reaction turbine
b) Steam turbine
c) Francis turbine
d) Pelton wheel
d) Pelton wheel
- What do you call a fan in which the fluid is accelerated parallel to the fan axis?
a) Axial centrifugal fan
b) Mixed flow centrifugal fan
c) Radial centrifugal fan
d) Francis type fan
a) Axial centrifugal fan
- It represents the loss due to mechanical friction of the moving parts of the engine, and expressed as horsepower. How do you call this?
a) Indicated Hp
b) Brake Hp
c) Combined Hp
d) Friction Hp
d) Friction Hp
- How do you call a device or engine which continually and indefinitely discharged more energy than it receives?
a) Carnot engine
b) Generating machine
c) Stirling engine
d) Perpetual motion machine
d) Perpetual motion machine
- In plotting the bHp versus speed in a wide- open throttle test for a spark ignition engine, the bHp curve:
a) is a Straight line.
b) tends to concave downward
c) has no characteristic shape
d) tends to concave upward
b) tends to concave downward
- Upon entering the boiler room, you find the water out of the glass, the safety valve blowing off strong, and a fire under the boiler. Your first action would be to:
a) Remove the fire with draft and damper open
b) Cool the boiler down completely
c) Prevent priming by not raising the safety valve or making change in operating of engines or boiler
d) Cool the boiler down completely and prevent priming by not raising the safety valve
a) Remove the fire with draft and damper open
- The A.S.M.E. Boiler code for boiler shells requires a tensile strength of which of the following, in psi?
a) 10000 to 20000
b) 25000 to 45000
c) 55000 to 63000
d) 70000 to 85000
c) 55000 to 63000
- The best time to blow a boiler down is:
a) Once a day when the load is lightest
b) Once a day under full load
c) When the chemical concentration is greatest
d) Once a shift
c) When the chemical concentration is greatest
149.In performing a hydrostatic test on an existing power boiler, the required test pressure must be controlled so that it is not exceeded by more than:
a) 2%
b) 4%
c) 6%
d) 8%
a) 2%
150.The first step to take in planning a preventive maintenance program is to:
a) Replace all electric wiring
b) Make an equipment inventory
c) Replace all pump seals
d) Repair all equipment which is not in operation
b) Make an equipment inventory
- Which of the following is the most important consideration in a fire prevention program?
a) Train the staff to place flammable in fireproof containers
b) Know how to attack fires regardless of size
c) See that halls, corridors, and exits are not blocked
d) Detect and eliminate every possible fire hazard
d) Detect and eliminate every possible fire hazard
- Which of the following types of portable fire extinguisher is recommended as most effective for putting out oil fires?
a) Pump tank type
b) Cartridge actuated type
c) Soda acid type
d) Foam type
d) Foam type
- Which of the following are the four stages of the warning system designated by the high air pollution alert warning system?
a) Initial, chronic, acute, penetrating
b) Forecast, alert, warning, emergency
c) light, medium, heavy, extra heavy
d) Early, moderate, severe, toxic
b) Forecast, alert, warning, emergency
- The chemical most commonly used to speed sedimentation of sewage is known as:
a) Lime
b) Copper sulfate
c) Sulfuric acid
d) Methylene blue
a) Lime
155.Most of the bacteria in sewage are:
a) Saprophytic
b) Dangerous
c) Parasitic
d) Pathogenic
a) Saprophytic
- One of the two types of non-material nuclear radiation is:
a) Gamma radiation
b) Transmutation radiation
c) Walton radiation
d) Betatron radiation
a) Gamma radiation
- Which of the following is not a qualification for an applicant for ME board examination?
a) A certified plant mechanic
b) At least 18 years old
c) A holder of BSME degree
d) A citizen of the Philippines
a) A certified plant mechanic
- A thermo hydraulic feed water regulator is used to regulate the flow of water to a drum type boiler. The amount of water input to the boiler is controlled in proportion to the:
a) Boiler load
b) Setting of the feed pump relief valve
c) Amount of water in the outer tube that flashes into steam
d) Water level in the drum
d) Water level in the drum
- The standard capacity rating conditions for any refrigeration compressor is:
a) 50F, 19.6 psig for the suction 860F, 154.5 psig for the discharge
b) 50F, 9.6 psig for the suction 960F, 154.5 psig for the discharge
c) 100F, 9.6 psig for the suction 960F, 144.5 psig for the discharge
d) 50F, 19.6 psig for the suction 960F, 134.5 psig for the discharge
a) 50F, 19.6 psig for the suction 860F, 154.5 psig for the discharge
- In accordance with the air pollution control code, no person shall cause or permit the emission of air contaminants from a boiler with a capacity of 500 million BTU sulfur dioxide content of more than:
a) 300 parts per million by volume undiluted emissions measured at 15 percent excess air
b) 200 parts per million by volume of undiluted emissions measured at 10 percent excess air
c) 200 parts per million by volume undiluted emissions measured at 15 percent excess
air
d) 300 per million by volume undiluted emissions measured at 10 percent excess air
b) 200 parts per million by volume of undiluted emissions measured at 10 percent excess air