IBONG TIRIRIT (PIPE II) - Refrigeration Past Paper PDF

IBONG TIRIRIT (PIPE II) a) Refrigerant b) Absorbent  In Refrigeration, how do you call a heat exchanger in which low-...

IBONG TIRIRIT (PIPE II) a) Refrigerant b) Absorbent  In Refrigeration, how do you call a heat exchanger in which low- c) Coolant pressure refrigerant boils or vaporizes, thus absorbing heat that d) Analyzer was removed from the refrigerated area by the cooling medium (water)? Answer: a) Refrigerant. Water serves as refrigerant while the lithium bromide serves as the absorbent. In ammonia solution a) Evaporator absorption refrigeration system, water serves as the absorbent b) Chiller while ammonia serves as the refrigerant. c) Cooler d) Flooded Evaporator  In the absorption refrigeration system, is a pressure vessel mounted above the generator through which the vapor leaving the generator pass. How do you call this component? Answer: b) Chiller. In refrigeration application, the appropriate term used for evaporator is chiller. a) Absorber b) Analyzer  It is a type of refrigeration system where only part of the c) Rectifier circulated refrigerant is evaporated, with the remainder being d) Reflux separated from the vapor and then recirculated. How do you call this system? Answer: b) Analyzer or bubble column a) Absorption refrigeration system  In the absorption refrigeration system, it is the inlet part of the b) Vacuum refrigeration system condenser, cooled by a separate circuit of cooling water or strong c) Vapor-compression refrigeration system aqua. It condenses a small part of the vapor leaving the bubble d) Flooded refrigeration system column and returns it as a liquid to the top of baffle plate. This ensures that the vapor going to the condenser is lowered in Answer: d) Flooded refrigeration system temperature and enriched in ammonia. What is this component?  How do you call the ice formation on a refrigeration system at a) Reflux the expansion device, making the device inoperative? b) Analyzer c) Rectifier a) Ice formation d) Absorber b) Freeze-up c) Freezing Answer: c) Rectifier. Reflux does about the same thing by d) Pump-down providing a small flow of condensed ammonia liquid to the top plate of the bubble column, but does not require a separate Answer: b) Freeze-up cooling circuit.  In a lithium bromide solution absorption refrigeration system, which of the following is the function of water? 1|Page  Which of the following is a scale of temperature in which the under a pressure below atmospheric. This is sometimes referred melting point of ice is taken as 0 o and the boiling point of water to as: is 80o? a) Halogenated refrigerant a) Reaumur Scale b) Freon refrigerant b) Carrene Scale c) Vacuum refrigerant c) Genetron Scale d) Halocarbon refrigerant d) Frigorie Scale Answer: c) Vacuum refrigerant Answer: a) Reaumur Temperature Scale  It is any one of a group of refrigerants that have been developed  How do you call the mixtures or substances that are used in since about 1925 to overcome the irritating or toxic effects of laboratory methods of producing a drop in temperature? The refrigerants, such as ammonia and sulfur dioxide and the high most common example is the mixture of ice and salt. condensing pressures required with carbon dioxide. How do you call these refrigerants? a) Calorific mixture b) Water-ammonia mixture a) Halogenated refrigerants c) Frigorific mixture b) Freon refrigerants d) Hygroscopic mixture c) Vacuum refrigerants d) Halocarbon refrigerants Answer: c) Frigorific mixture Answer: a) Halogenated refrigerants Note: Adding of 10 % salt (NaCl), by weight, to water lowers its freezing point from 32 oF to 18.7 oF.  This refrigeration system component combines the functions of a cooling tower and a condenser. It consists of a casing enclosing a  It the maximum temperature of any gas or vapor at which it may fan or blower section, water eliminators, refrigerant condensing be condensed into a liquid; above this temperature, it is coil, water pan, float valve, and spray pump outside the casing. impossible to condense regardless of the pressure applied. How How do you call this component? do you call this temperature?  a) Water-cooled condenser a) Saturation temperature b) Evaporative condenser b) Superheated temperature c) Atmospheric condenser c) Critical temperature d) Chiller d) Dew point temperature Answer: b) Evaporative condenser Answer: Critical temperature  It refers to a factor used in calculating the over-all heat transfer  Any refrigerant that exists as a liquid under normal atmospheric through the tube walls of a condenser tube or other heating pressure and temperature must be vaporized in an evaporator surface. It includes the sum of the heat-transfer rate of the layer 2|Page  of dirt and foreign material that builds up on the water side of Answer: d) The valve of the controlled condition actually the tube. What is this factor? under steady state conditions a) Cooling factor  A pneumatic temperature control is used on the steam supply to b) Contact factor a non-storage heat exchanger that heats water serving an office c) By-pass factor heating system. What is referred to as “manipulated variable”? d) Fouling factor a)The water being heated Answer: d) Fouling Factor b)The air signal from the controller to the valve actuator c)The steam supply  It is a refrigeration system evaporator which is arranged with a d)The temperature of the air being heated tank or a single drum (accumulator) located above the coil so that the inside of the evaporator is full of refrigerant. How do Answer: c) Manipulated variable is referred to as the steam you call this type of evaporator? supply a) Flooded evaporator  Which of the following valves is the one designed to allow a b) Dry evaporator fluid to pass through in one direction? c) Cooing coil evaporator d) Headered coil evaporator a) Globe valve b) Gate valve Answer: a) Flooded evaporator c) Float valve d) Check valve  What is the standardized term used by the industry to describe any device that meters or regulates the flow of liquid refrigerant Answer: d) Check valve to an evaporator?  How do you classify a solenoid valve? a) Refrigerant control b) Expansion valve c) Throttling valve d) Capillary tube a) A thermal valve b) A magnetic stop valve Answer: b) Expansion Valve c) A bellows valve d) A bi-metallic valve  Define a “control valve”. Answer: b) A solenoid valve is classified as magnetic stop a) The value set on the scale of the control system in order to valve obtain the required condition b) The quantity or condition of the controlled medium  What is a thermostat? c) The flow or pressure of the steam (or fluid) being manipulated d) The valve of the controlled condition actually maintained a) A temperature-operated switch under steady state conditions b) A pressure-operated switch c) A superheat-operated switch 3|Page  d) A back pressure-operated switch c) Connections d) The trap must be the same size as the condensate drain Answer: a) A temperature –operated switch line  Which of the following is the one of the main purposes of Answer: b) Air venting, plant performance, flow capacity refractory in a boiler furnace? and reliability a) Help preheat the air for the furnace  Can temperature controlled applications be trapped? b) Help preheat the feed water c) Protect economizer from excessive heat a) Traps should not be fitted under any circumstances d) Prevent excessive furnace heat losses b) Only if there is no lift after the trap c) If the pressure on the trap is always higher than backpressure Answer: d) Prevent excessive furnace heat losses d) Pumps should always be fitted to remove condensate  Balance pressure traps are what type of steam trap? Answer: c) If the pressure on the trap is always higher than back pressure a) Thermodynamic b) Mechanical  Unless they are designed to flood, what is the important when c) Thermostatic removing condensate from heat exchangers? d) They do not belong to any specific type of trap family a) Condensate is allowed to sub-cool before reaching the trap Answer: c) Thermostatic b) Condensate is removed at steam temperature c) Condensate should back-up into the steam pipe d) That the trap is fitted level with or above the heater outlet  What is a characteristic feature of thermodynamic steam traps? Answer: b) Condensate is removed at steam temperature a) They pass condensate at steam temperature  How is flash steam produced? b) They operate by holding back condensate until it has cooled c) They cannot be fitted outside a) From condensate passing from high to low pressure systems d) They can only be fitted on low pressure steam systems b) From saturated steam c) From superheated steam Answer: b) they operate by holding back condensate until it d) From steam mixed with high temperature air has cooled Answer: a) From condensate passing from high to low pressure  What are the main considerations for steam trap selection? system a) Price  Are steam traps required to pass air? b) Air venting, plant performance, flow capacity and reliability a) Steam traps should not pass air under any circumstances 4|Page  b) Only when the trap has passed all the condensate  When adding the refrigerant in a refrigeration system, it shall be c) Air should be removed as soon as it reaches the trap charge into which of the following parts of the system? d) Only on high pressure steam system a) High pressure side Answer: c) Air should be removed as soon as it reaches the trap b) Low pressure side c) Low and high pressure side  How do you call a system employing open sprinklers attached to d) Compressor discharge line a piping system connected to a water supply through which is opened by the operation of a fire detection system installed in Answer: b) Low pressure side the same areas as the sprinklers?  Why is a boiler feed tank heated to approximately 85 oC? a) Mechanical sprinkler b) Automatic system a) To reduce the energy required to raise steam c) Wet pipe system b) To reduce the content of total dissolved solids in the water d) Deluge system supplied to the boiler c) To reduce the gas content of the water Answer: d) Deluge system d) To reduce the content of suspended solids in the water  What is probably the first consideration when selecting a control Answer: c) To reduce the gas content of the water system?  What is used to dry air? a) What degree of accuracy is required? b) Is the control for heating or cooling? a) A separator c) Is a two or three port valve required? b) A strainer d) In the event of power failure, must the valve fail-open or fail- c) A steam trap closed? d) A tee piece Answer: d) In the even of power failure, must the valve fail- Answer: a) A separator open or fail-closed?  What causes water hammer in the boiler?  Which of the following ranges of humidity ratio is used for comfort air conditioning? a) Suspended water droplets b) An air/water mixture a) 50 to 55 % b) 55 to 60 % c) Strainers fitted on their sides c) 60 to 65 % d) Slugs of water in the steam d) 45 to 50 % Answer: d) Slugs of water in the steam Answer: b) RH = 55 % to 60 %  How does air enter a steam system? 5|Page a) Through joints, on shut down of the steam system b) The heat output would be greater because steam at 3 bar g has b) With make-up water to the boiler feedtank a greater volume than steam at 7 bar g. c) With condensate entering the boiler feedtank c) Less weight of steam would be required because steam at 3 d) Both a, b, & c bar g has a higher enthalpy of evaporation than 7 bar g. d) The output would be reduced because the difference in Answer: d) All of the items stated from a to c temperature between the steam and product is reduced.  Why should strainers installed on steam lines be fitted on their Answer: d) sides?  For any particular tank temperature how does the heat loss from a) To prevent the build-up of water in the strainer body the lid of a closed tank compare with that of bottom? b) To trap more dirt c) To reduce the frequency of cleaning a) They are approximately double those from the bottom d) To provide maximum screening area for the steam b) Losses from the top are approximately double those from the bottom c) Losses from the bottom are approximately double those from Answer: a) To prevent the build-up of water in the strainer the top body d) Losses from the top are approximately 4 times those from the bottom  What is the result of using a heat exchanger rating to calculate its steam consumption? Answer: b) Losses from the top are approximately double those from the bottom a) The true connected heat load may be different from the rated figure.  What is the disadvantage of heating a tank by direct steam b) The rating does not take account of the temperature of the injection? secondary medium c) The rating is based on a steam pressure of 1.0 bar a) It agitates the solution d) The rating does not allow for condensate forming in the heat b) Some of the enthalpy of water is used exchanger c) Steam traps are not required d) It dilutes the tank content Answer: a) The true connected heat load may be different from the rated figure Answer: d) It dilutes the tank content  The existing 2000 TR chiller at a large hospital, where you are  A heat exchanger has a design rating based on a working assigned as Engineer, must be replaced. Which of the following pressure of 7 bar g. What would be the effect of supplying the types most likely to be installed? exchanger with steam at 3 bar g? a) Screw chiller a) The heat output would be greater because the enthalpy of b) Scroll Chiller evaporation at 3 bar g is higher than at 7 bar g. c) Reciprocating chiller 6|Page  d) Centrifugal chiller a) The tank contains a corrosive solution Answer: d) Centrifugal chiller b) When agitation of the tank solution is required c) When steam locking the trap draining a base coil could occur Note: Centrifugal chillers are generally selected for their high d) When good heat distribution is required coefficient of performance, good part-load performance, and cooling capacity. The economics of large-scale applications Answer: a) The tank contains a corrosive solution (such as hospital) generally favor more efficient machines such centrifugal chillers. In this case, a centrifugal chiller is  What range of ‘U’ values would you apply for mild steel jacket also the only one of the types listed that can provide the around a stainless steel tank containing a water and detergent needed capacity. solution?  Refrigeration condensers are rated based upon their ability to a) 285 – 480 reject the total heat that comes from which of the following? b) 450 – 1140 c) 850 – 1700 a) Compressor work and net refrigeration effect d) 285 – 850 b) Superheating c) Subcooling Answer: b) 450 to 1140 kJ/kg-oK d) Compressor work  A tank is to be heated by direct steam injection. How will the Answer: a) Compressor Work and net refrigeration effect quantity of heat required compare with steam coil heating? Note: All the heat removed by a refrigeration system, a) It depends on the temperature of the water being heated including the heat it introduces due to the work of the b) More heat will be required compressor, must ultimately be rejected to the outdoor c) The same amount of heat will be required environment by the condenser. So refrigeration effect and d) Less heat will be required compressor work must be considered. Answer: c) The same amount of heat will be required  A published ‘U’ value from a steam coil to a water based solution is given as 550 – 1300 W/m 2-oC. When would be figure  Which of the following parameters has the greatest limiting near the lower end of the range be used? effect on the thermal performance of an open, evaporative cooling tower? a) When the steam is known to be of good quality b) For short coils a) Wet-Bulb temperature c) For small diameter coils b) Dry-Bulb temperature d) When scaling or fouling of the coil takes place c) Range d) Approach Answer: d) When scaling or fouling of the coil takes place Answer: a) Wet-bulb temperature  Steam coils should enter and leave the top of a tank when: 7|Page  Note: It is not possible to cool the water below the air’s wet-bulb a) Zone temperature. Thus, the WB temperature, more than any other b) Room parameter, sets the absolute limit on the cooling tower’s c) Space capacity. d) Plenum  Air enters a cooling tower at 10 oC DB and 9.5 oC WB Answer: c) Space temperature. It leaves the tower saturated at 21 oC. Which condition is a likely outcome of this?  It is an enclosed or partitioned space that is usually treated as a single load. If conditioned, it often has an individual control a) Sublimation system. What is this? b) Condensation c) Adsorption a) Zone d) Fog b) Room c) Space Answer: d) Fog d) Plenum Note: Answer: b) Room  The process has the potential to create fog, which consists of liquid droplets suspended in the atmosphere.  It represents the rate, in Btu/hr or W, at which heat enters a  Adsorption is a process in which molecules of gas or conditioned space from an external source or is released to the liquid are extracted from an atmosphere. But it does not space from an internal source during a given time interval. indicate suspended moisture droplets such as those that characterize fog. a) Space heat gain b) Space cooling load  It is a space, or several rooms, or units of space having some sort c) Space heating load of coincident loads or similar operating characteristics. It may or d) Space heat extraction rate may not be an enclosed space, or it may consist of many partitioned rooms. How do you call this? Answer: a) Space heat gain a) Zone  It is the rate, in Btu/hr or W, at which heat must be removed b) Room from a conditioned space so as to maintain a constant c) Space temperature and acceptable relative humidity. Its sensible load d) Plenum component is equal to the sum of the convective heat transfer from the surfaces of the building envelope, furnishings, Answer: a) Zone occupants, appliances, and equipment. How do you call this?  In air conditioning, it indicates either a volume or a site without a) Space heat gain a partition or a partitioned room or group of rooms. How do you b) Space cooling load call this? c) Space heating load d) Space heat extraction rate 8|Page  o Fm2 Answer: b) Space cooling load c) 1 clo  0.275 W o Fm2  A process that the body uses to convert energy in food into heat d) 1 clo  190 kW and work, or it is the process that determines the rate at which energy is converted from chemical to thermal form within the body. o F  ft 2  Hr Answer: a) 1 clo  0.880 Btu a) Metabolism b) Eating  What is the basic index used to describe the radiant conditions in c) Body food processing a space, it is the mean temperature of individual; exposed d) Blood circulation surfaces in the environment? Answer: a) Metabolism a) Index temperature b) Mean radiant temperature  What is a body insulation that is usually described as a single c) Space temperature equivalent uniform layer over the whole body? d) Dry bulb temperature a) Skin Answer: b) Mean Radiant Temperature b) Blood c) Clothing  In order to avoid cavitation in a centrifugal pump, which of the d) Water following is true? Answer: c) Clothing a) Installation NPSH  pump NPSH b) Installation NPSH  pump NPSH  What is the insulating value of clothing? c) Installation NPSH < pump NPSH d) Installation NPSH should be negative a) Btu unit b) Clo units c) Calorie unit Answer: a) Installation NPSH  pump NPSH d) Frigorie Unit  What always accompanies an isentropic expansion of steam? Answer: b) Clo units a) An increase in entropy  Which of the following is the value of clo units? b) An increase in enthalpy c) A decrease in entropy o F  ft 2  Hr d) A decrease in enthalpy a) 1 clo  0.880 Btu o Answer: d) A decrease in enthalpy Fm2 b) 1 clo  100 kW 9|Page  Those substance that are particularly variable in the moisture  What is the rate, in Btu/h or W, at which heat must be added to content that they can possess at different times. the conditioned space to maintain a constant temperature and sometimes a specified relative humidity? a) Wet materials b) Hygroscopic materials a) Space heat gain c) Gross materials b) Space cooling load d) Bone-dry-weight material c) Space heating load d) Space heat extraction rate Answer: b) Hygroscopic material Answer: c) Space heating load  What is the advantage of a pressurized deaerator over an atmospheric deaerator?  Space heat extraction rate Qex, Btu /h (W), is the rate at which heat is actually removed from the conditioned space by the air a) A boiler feed tank is no longer required system. Its sensible heat rate component is equal to the sensible b) Less over all energy will be required to produce the steam cooling load only when the space air temperature remains c) It can be fitted at ground level constant. d) It removes more oxygen a) Space heat gain Answer: d) It removes more oxygen b) Space cooling load c) Space heating load  In proximate analysis, the coal analysis is consisting of moisture d) Space heat extraction rate content, fixed carbon, ash, and which of the following? Answer: d) Space heat extraction rate a) Sulfur b) Hydrogen  It is the rate, in Btu/h or W, of heat transfer at the coil. Its c) Nitrogen cooling load component is the rate at which heat is removed by d) Volatile matter the chilled water flowing through the coil or is absorbed by the refrigerant inside the coil. What do you call this? Answer: d) Volatile matter a) Coil load  How do you call the heating value of the fuel if the water in the b) Heating coil load products of combustion is in the liquid state? c) Refrigerating load d) Cooling load a) Higher heating value b) Lower heating value Answer: a) Coil load c) Proximate heating value d) Gravimetric heating value  It is the rate, in Btu/hr or W, at which heat is added to the conditioned air from the hot water, steam, or electric heating Answer: a) Higher heating value elements inside the coil. 10 | P a g e  a) Coil load b) Heating coil load a) Automatic Valve c) Refrigerating load b) Automatic flow meter d) Cooling load c) Thermostat d) Pyrometer Answer: b) Heating Coil Load Answer: a) Automatic Valve  What is the rate, in Btu/hr or W, at which heat is absorbed by the refrigerant at the evaporator. For central hydronic systems, it  Assume that you are checking the water level in a boiler which is is the sum of the coil load plus the chilled water piping heat on the line in a power plant. Upon opening the gage cocks, you gain, pump power heat gain, and storage tank heat gain. For determine that the water level was above the top gage cock. Of most water systems in commercial buildings, the water piping the following actions, the best one to take first in this situation and pump power heat gain is only about 5 to 10 percent of the would be to: coil load. In an air conditioning system using DX coil(s), it is equal to the DX coil load. a) Shut-off the fuel and air supply b) Surface-blow the boiler a) Coil load c) Close the steam outlet valve from the boiler b) Heating coil load d) Increase the speed of the feed water c) Refrigerating load d) Cooling load Answer: c) Close the steam outlet valve from the boiler Answer: c) Refrigerating load  It is a component in a hydro plant that absorbs water hammer during load fluctuations and serves as an auxiliary reservoir  It is a humidity sensor used to measure relative humidity, dew during high load demands. What is this component? point, or absolute humidity of ambient or moving air. This device could be mechanical or electronic. How do you call this? a) Spillway b) Dam a) Hydrometer c) Surge tank b) Hygrometer d) penstock c) Psychrometer d) Barometer Answer: c) Surge Tank Answer: b) Hygrometer  It is a bituminous coal that contains plenty of hydrocarbons, forming lumped masses when burned. This coal is ideal for  It is a device designed to control the flow of steam, water, gas, or forming carbonaceous gases for reduction of ore. What do you other fluids. It can be considered a variable orifice positioned by call this coal? an actuator in response to impulses or signals from the controller. It may be equipped with either a throttling plug, V- a) Coking or coking coal port, or rotating ball specially designed to provide a desired flow b) Free burning coal characteristic. How do you call this device. 11 | P a g e  c) Peat coal a) Ash d) Lignite coal b) Color c) Carbon residue Answer: a) Coking or coking coal d) Coke  It is the temperature at which the oil vapors will continue to Answer: c) Carbon residue burn when ignited.  Petroleum oils, when cooled, may become plastic solids, either a) Fire point from wax formation or from the fluid congealing. With some b) Flash point oils, the initial wax crystal formation becomes visible at c) Ignition temperature temperatures slightly above the solidification point. When that d) Creep temperature temperature is reached at specific test conditions, it is known as the Answer: a) Fire point a) Cloud point  It is the temperature to which oil has to be heated until sufficient b) Pour point flammable vapor is driven off to flash when brought into c) Creep point momentary contact with a flame. How do you call this d) Flash point temperature? Answer: a) Cloud point a) Fire point b) Flash point c) Ignition temperature d) Creep temperature  It is the temperature at which cooled oil will just flow under specific test conditions; and it indicates the lowest temperature Answer: b) Flash point at which a lubricant can readily flow from its container. How do you call this temperature?  The color of a lubricating oil is obtained by reference to transmitted light; the color by reflected light is referred to as: a) Cloud point b) Pour point a) Bloom c) Creep point b) Reflection d) Flash point c) Deflection d) Residue Answer: b) Pour point Answer: a) Bloom  It is a term indicating the measure of acidic components in oils; and was original intent to indicate the degree of refining in new  How do you call the material left after heating an oil under oils, and to follow the development of oxidation in service, with specified conditions at high temperature, and is useful as a its effects on deposit formation and corrosion. What is this? quality control tool in the refining of viscous oils, particularly residual oils? a) Neutralization number b) Total base number 12 | P a g e  c) Total acid number d) Neutralization number and total acid number  How do you call these engine oil additives used to prevent attack on sensitive bearing metals? Answer: d) Neutralization number and total acid number a) Detergents  How do you call a measure of alkaline components in oils, b) Dispersants especially those additives used in engine oils to neutralize acids c) Oxidation inhibitors formed during fuel combustion? d) Corrosion inhibitors a) Neutralization number Answer: d) Corrosion inhibitors b) Total base number c) Total acid number  These are engine oil additives used to prevent or reduce deposits d) Neutralization number and total acid number and corrosion by neutralizing combustion by-product acids. What are these additives? Answer: b) Total base number a) Detergents  These are materials with low coefficients of friction compared to b) Dispersants metals, and they are used to reduce friction and wear in a variety c) Oxidation inhibitors of applications. There are a large number of such materials, and d) Corrosion inhibitors they include graphite, molybdenum disulfide, polytetrafluoroethylene, talc, graphite fluoride, polymers, and Answer: a) Detergents certain metal salts. How do you call these materials?  What is the molecular attraction of layers of an unlike matters? a) Greases b) Liquid lubricants a) Adhesion c) Solid lubricants b) Cohesion d) Powder lubricants c) Advection d) Convection Answer: c) Solid lubricants Answer: a) Adhesion  These are engine oil additives used to help keep the engine clean by solubilizing and dispersing sludge, soot, and deposit  How do you call these engine oil additives used to prevent precursors. How do you call these oil additives? attack on iron and steel surfaces by condensed moisture and acidic corrosion products, aggravated by low-temperature stop- a) Detergents and-go operation? b) Dispersants c) Oxidation inhibitors a) Detergents d) Corrosion inhibitors b) Dispersants c) Oxidation inhibitors Answer: b) Dispersants d) Rust inhibitors 13 | P a g e  Answer: d) Rust inhibitors a) Anti-wear additives b) Friction modifiers  How do you call these engine oil additives used to help enable c) Oxidation inhibitors adequate low-temperature flow, along with sufficient viscosity d) Rust inhibitors at high temperatures? Answer: b) Friction modifiers a) Viscosity-index improvers b) Pour point dispersants  How do you call an opening where hot source of energy from c) Oxidation inhibitors the earth is harnessed? d) Rust inhibitors a) Crater Answer: a) Viscosity-index improvers b) Hot water source c) Fumarole  These oil additives are used to minimize wear under boundary d) Volcano opening lubrication conditions, such as cam and lifter, and cylinder-wall and piston-ring surfaces. Answer: c) Fumarole a) Anti-wear additives  At standard atmospheric conditions, what is the approximate b) Pour point dispersants speed of sound? c) Oxidation inhibitors d) Rust inhibitors a) 336 m/s b) 363 m/s Answer: a) Anti-wear additives c) 633 m/s d) 346 m/s  These are engine oil additives used to allow air to break away easily from the oil. Answer: a) 336 m/s a) Anti-wear additives  The speed of sound is also called as: b) Defoamants c) Oxidation inhibitors a) Sound velocity d) Rust inhibitors b) Acoustic velocity c) Subsonic velocity Answer: b) Defoamants d) Critical velocity Answer: b) Acoustic velocity  These engine oil additives are used to improve fuel efficiency by  This is the velocity at which a small pressure wave moves reducing friction at rubbing surfaces. How do you call these oil through a fluid. How do you call this velocity? additives? 14 | P a g e  a) Sonic velocity Answer: b) 75 % sensible heat and 25 % latent heat b) Subsonic velocity c) Supersonic velocity  The hardness of ground water required as feed water for a boiler d) Hypersonic velocity is 0 – 10 ppm (part per million), which of the following is the range of alkalinity requirement? Answer: a) Sonic Velocity a) pH 9 to pH 10  Which of the following is the speed of light? b) pH 6 to pH 10 c) pH 10 to pH 11 a) 2.998 x 108 m/s d) pH 8 to pH 10 b) 2.998 x 109 c) 2.998 x 1010 m/s Answer: c) pH 10 to pH 11 d) 2.998 x 107 m/s  As used in the Revised PSME Code for Boilers and Pressure Answer: a) 2.998 x 108 m/s Vessels, it is any boiler which does not exceed any of the following limits: 405 mm inside diameter, 1065 mm overall  What can you say about entropy in the universe? length of outside to outside heats at center, 1.85 m2 of water heating surface, and 7.03 kg/cm2 maximum allowable working a) Entropy is always increasing pressure. What is this boiler? b) Entropy is decreasing c) Entropy will zero at the end of time a) Power boiler d) Entropy is stagnating b) Portable boiler c) Miniature boiler Answer: a) Entropy is always increasing d) Locomotive boiler  Which of the following is the chemical formula of butane? Answer: c) Miniature boiler a) C2H5 b) C10H16 c) C4H10  It is a closed vessel in which steam or other vapor (to be used d) C3H6 externally to itself) is generated by the direct application of heat used for power generation. How do you call this boiler? Answer: c) C4H10  If the sensible heat ratio is 0.75, what does it mean? a) Power boiler b) Portable boiler a) 75 % latent heat and 25 % sensible heat c) Oil-fired boiler b) 75 % sensible heat and 25 % latent heat d) Miniature boiler c) 25 % latent and sensible heat and 75 % latent heat d) 75 % sensible and latent heat and 25 % sensible heat Answer: a) Power boiler 15 | P a g e  It is a closed vessel intended for use in heating water of for application of heat to generate steam or other vapor to be used externally from it. What do you call this pressure vessel? a) Boiler or steam generator b) Fired pressure vessel c) Unfired pressure vessel d) Pressurized tank  When new boilers are installed in either existing or new Answer: a) Boiler or steam generator buildings, a minimum height of at least ______ shall be provided between top of the boiler proper and ceiling.  What do you call a vessel in which pressure is obtained from external sources, or from an indirect application of heat? a) 1050 mm b) 2130 mm a) Boiler or steam generator c) 1250 mm b) Fired pressure vessel d) 2050 mm c) Unfired pressure vessel d) Pressurized tank Answer: b) 2130 mm Answer: c) Unfired pressure vessel  For power boilers, when the tensile strength of steel is not known, it shall be taken as 379 MPa and which of the following  It is any boiler or unfired pressure vessel constructed, installed, for the wrought iron?\ placed in operation but subject to annual inspection. What do you call this? a) 379 N/mm2 b) 310 MPa a) Miniature boiler c) 450 MPa b) Existing installation d) 521 N/mm2 c) New boiler d) Portable boiler Answer: b) 310 MPa Answer: b) Existing installation  Name one characteristic feature of mechanical steam traps.  It is a boiler that has been inspected and declared unsafe to a) They pass condensate at steam temperature operate or disqualified, marked and marked indicating its b) They operate by sensing condensate temperature rejection. How do you call this boiler? c) They can be fitted into any position d) They are not affected by increasing back pressure a) Second hand boiler b) Reinstalled boiler Answer: b) They pass condensate steam temperature c) Condemned boiler d) Unfired boiler  In a mechanical steam trap, why is a float trap better at venting air than an inverted bucket trap? Answer: c) Condemned boiler 16 | P a g e  a) A float can quickly adjust to the presence of air b) A float is fitted with an automatic air vent a) An inverted bucket trap with an internal check valve c) A float trap does not vent air better than bucket trap mechanism d) The air vent orifice is adjustable on a float trap b) A balanced pressure steam trap c) A float trap with automatic air vent Answer: b) A float fitted with automatic air vent d) A float trap with steam lock release mechanism  In a mechanical steam trap, what added benefit does the Answer: b) A balanced pressure steam trap automatic air vent offer to a float trap?  What is a common cause of waterhammer in drying coils? a) It stops the trap from freezing in cold weather b) The trap can be use on larger backpressures a) Wet steam supplied to the coil c) It significantly increases the cold start-up capacity of the trap b) Too low a steam pressure onto the coil d) The condensate orifice can be the same size for all pressure c) Condensate has to lift after the steam trap gauges d) The coil falling in the direction of steam flow Answer: c) It significantly increases the cold start-up capacity Answer: c) Condensate has to lift after the steam trap of the trap  Which of the following statements is true?  In a mechanical steam trap, what advantage does a bucket trap have over a float type? a) Bimetallic steam traps are an ideal choice for rotating cylinders a) It is able to withstand waterhammer b) Rotating cylinders can not suffer from steam locking b) It can be used on higher pressure c) Strainers cannot be fitted to float traps which have a steam c) It can discharge air freely lock release d) It cannot lose its water seal d) Air vents around the thermodynamic and inverted bucket traps can considerably improve start-up times Answer: b) it can be used on higher pressure Answer: d)  A heat exchanger is designed to operate without waterlogging of the steam space. What is the usual choice of trap for its drainage?  Name the principle cause of waterhammer? a) Thermostatic trap a) Water particles suspended in steam b) Inverted bucket trap b) Water allowed to build up in pipes c) Thermodynamic trap c) Water droplets carried along the insides of pipes d) Float trap with thermostatic air vent d) Wet steam passing through steam traps Answer: d) Float trap with thermostatic air vent Answer: b) Water allowed to build up in pipes  Which is the best trap to use when steam locking can occur?  What effect does steam locking have on rotating machinery? 17 | P a g e   The maximum allowable working pressure of a non-code steel or a) None at all wrought iron heating boiler of welded construction shall not b) It reduces the drying rate of drying cylinders exceed to which of the following pressures? c) It increases the drying rate of drying cylinders d) It causes the steam trap to air bind a) 1 atmosphere b) 1 Bar Answer: b) It reduces the drying rate of drying cylinders c) 100 kPa d) 2 gage pressure  What do you call a boiler of which both the location and ownership have been changed after primary use? Answer: b) 1 bar a) Second hand boiler  What do you call a refrigeration system in which the refrigerant b) Surplus boiler gas evolved in the evaporator is taken up in an absorber and c) Miniature boiler released in a generator upon the application of heat? d) Reinstalled boiler a) Absorption refrigeration system Answer: a) Second hand boiler b) Cascade refrigeration system c) Flooded refrigeration system  It is a boiler removed from its original setting and re-erected at d) Steam jet refrigeration system the same location or erected at a location without change of ownership. How do you call this boiler? Answer: a) Absorption refrigeration system a) Second hand boiler  What do you call a shut-off valve other than a valve for b) Surplus boiler controlling the flow of refrigerant in a refrigeration system? c) Miniature boiler d) Reinstalled boiler a) Fusible valve b) Stop valve Answer: d) Reinstalled boiler c) Check valve d) Relief valve  Each miniature boiler shall be equipped with which of the following for the determination of water level? Answer: b) Stop valve a) Safety valve  What is a device, used in refrigeration system, having a b) Fusible plug predetermined temperature fusible member for the relief of c) Water gage glass pressures? d) Pressure gages a) Fusible valve Answer: c) Water gage glass b) Stop valve c) Check valve d) Relief valve 18 | P a g e  b) rk < re Answer: a) Fusible valve c) rk = re d) re is not considered in the spark-ignition engine  It is a measure of the lack of potential or quality of energy; and once that energy has been exchanged or converted, it cannot Answer: c) rk = re revert back to a higher level. What is this?  It is the generic term given to a family of solid fuels with high a) Specific heat carbon content. How do you call this? b) Entropy c) Internal energy a) Solid fuel d) Molecular energy b) Coal c) Anthracite Answer: b) Entropy d) Bituminous  What do you call the method used to evaluate all welds Answer: Coal performed on pressure parts of boiler tube materials?  It is a boiler fuel created from the residue produced from crude a) Radiographic test petroleum after it has been distilled to produce lighter oils like b) Hydrostatic test gasoline, paraffin, kerosene, diesel or gas oil. What is this fuel? c) Vacuum test d) Orsat analysis a) Oil b) Kerosene Answer: a) Radiographic test c) Coke d) Peat  It is a boiler testing method that is used to verify the microstructure of the boiler tubes using optical microscopes. Answer: a) Oil How do you call this method?  What do you call a form of boiler fuel that is easy to burn, with a) Tube sampling very little excess air? b) Metallurgic replication  c) Radiographic testing a) Coal d) Optical testing b) Oil c) Gas Answer: b) metallurgic replication d) Bunker  Which of the following is true regarding the relation of r k and re Answer: c) Gas for spark-ignition engine, where rk = compression ratio while re = expansion ratio?  The second law of thermodynamics says that whenever energy is exchanged or converted from one form to another, the a) rk > re potential for energy to do work will be _________. 19 | P a g e  a) Decreased b) Increased a) Drag c) Zero d) Stagnant b) Lift Answer: a) Decreased c) Aero horsepower d) Terminal velocity  What is true about steam as it condenses? Answer: a) Drag a) It does so at constant entropy and temperature b) It does so at constant enthalpy and reducing temperature  It is a term used by automobile manufacturers to designate the c) Both enthalpy and entropy reduce and temperature remains power required to move a car horizontally at 50 mi/hr against constant the drag force. What is this? d) Both enthalpy and entropy increase a) Mechanical horsepower Answer: c) Both enthalpy and entropy reduce and temperature b) Aero horsepower remains cosntant c) Fuel power d) Fluid power  It is an increase in fluid pressure in a long pipe caused by a sudden velocity decrease, where the sudden decrease in velocity Answer: b) Aero Horsepower is caused by a valve closing.  A manufacturer claims that it has a COP of 2.0 when cooling a a) Aero dynamics food at 5 oC using ambient air at 30 oC as a heat sink. Is the claim b) Water hammer of the manufacturer valid? c) Terminal velocity d) Drag a) Yes b) No Answer: b) Water hammer c) Probably d) It needs experimental verification  It is an upward force that is exerted on an object (like flat plate, airfoil, rotating cylinder, etc.) as the object passes through a Answer: a) Yes, because the claimed COP of the manufacturer fluid. What do you call this? is lower than the COP of Carnot Refrigeration a) Drag  What can you say about the velocity of fluid at the center of the b) Lift pipe section? c) Aero horsepower d) Terminal velocity a) Maximum b) Minimum Answer: b) Lift c) Average d) Zero  What is a frictional force that acts parallel but opposite to the direction of motion of fluid? 20 | P a g e  Answer: a) Maximum, the velocity of the flowing fluid is Answer: d) Changes in enthalpic energy is converted into maximum at the pipe center changes in kinetic energy  Continuity equation is applicable to which of the following?  Generally steam turbines in power station operate at which of the following speeds? a) Viscous and unviscous fluids b) Compressibility fluids a) 3000 rpm c) Conservation of mass b) 1000 rpm d) Steady and unsteady flows c) 4000 rpm d) 500 rpm Answer: c) Conservation of mass Answer: c) 4000 rpm  Hygrometer is an instrument used to determine of which of the following?  Tidal power is the power generated from which of the following? a) Specific gravity of fluids b) Specific gravity of gases a) Waves of the ocean c) Specific gravity of liquids b) Thermal energy of ocean water d) Specific gravity of solids c) Raw sea water d) Rise and fall of tides Answer: a) Specific gravity of fluids Answer: d) Rise and fall of tides  At critical point of a pure substance, what is the value of latent heat?  Which of the following is an expression or equivalent of horsepower per ton of refrigeration? a) Maximum b) Minimum 4.715 a) c) Zero COP d) Below zero COP b) 4.715 Answer: c) Zero, at the critical point hg – hf = 0 c) COP x 4.715 1  Which of the following is a function of a steam nozzle? d) 4.715 x COP a) Converts kinetic energy into heat energy b) Changes internal energy into kinetic energy Answer: a) 4.715 divided by the COP c) Converts potential energy into heat energy d) Changes enthalpic energy into kinetic energy 21 | P a g e  It is the ratio of the amount of heat taken up by a substance to c) Combined Hp the temperature at which the substance exists. How do you call d) Friction Hp this? Answer: d) Friction Hp a) Internal energy b) Flow energy  How do you call a device or engine which continually and c) Enthalpy indefinitely discharged more energy than it receives? d) Entropy a) Carnot engine b) Generating machine Answer: d) Entropy c) Stirling engine d) Perpetual motion machine  Which of the following is a type of water turbine where a jet of Answer: d) Perpetual motion machine water is made to fall on the blades or buckets and due to the impulse of water the turbine starts moving?  In plotting the bHp versus speed in a wide open throttle test for a spark ignition engine, the bHp curve: a) Reaction turbine b) Steam turbine a) is a Straight line c) Francis turbine b) tends to concave downward d) Pelton wheel c) has no characteristic shape d) tends to concave upward Answer: d) Pelton wheel Answer: b) tends to concave downward  What do you call a fan in which the fluid is accelerated parallel to the fan axis?  Upon entering the boiler room, you find the water out of the glass, the safety valve blowing off strong, and a fire under the a) Axial centrifugal fan boiler. Your first action would be to: b) Mixed flow centrifugal fan c) Radial centrifugal fan a) Remove the fire with draft and damper open d) Francis type fan b) Cool the boiler down completely c) Prevent priming by not raising the safety valve or making Answer: a) Axial centrifugal fan change in operating of engines or boiler d) Cool the boiler down completely and prevent priming by not  It represents the loss due to mechanical friction of the moving raising the safety valve parts of the engine, and expressed as horsepower. How do you call this? Answer: a) Remove the fire with draft and damper open a) Indicated Hp  The A.S.M.E. Boiler code for boiler shells requires a tensile b) Brake Hp strength of which of the following, in psi? 22 | P a g e  a) Train the staff to place flammable in fireproof containers a) 10000 to 20000 b) Know how to attack fires regardless of size b) 25000 to 45000 c) See that halls, corridors, and exits are not blocked c) 55000 to 63000 d) Detect and eliminate every possible fire hazard d) 70000 to 85000 Answer: d) Detect and eliminate every possible fire hazard Answer: c) 55000 to 63000  Which of the following types of portable fire extinguisher is  The best time to blow a boiler down is: recommended as most effective for putting out oil fires? a) Once a day when the load is lightest a) Pump tank type b) Once a day under full load b) Cartridge actuated type c) When the chemical concentration is greatest c) Soda acid type d) Once a shift d) Foam type Answer: d) Foam type Answer: c) When the chemical concentration is greatest  Which of the following are the four stages of the warning system  In performing a hydrostatic test on an existing power boiler, the designated by the high air pollution alert warning system? required test pressure must be controlled so that it is not exceeded by more than: a) Initial, chronic, acute, penetrating b) Forecast, alert, warning, emergency a) 2% c) Light, medium, heavy, extra heavy b) 4% d) Early, moderate, severe, toxic c) 6% d) 8% Answer: b) Forecast, alert, warning, emergency Answer: a) 2%  The chemical most commonly used to speed sedimentation of sewage is known as:  The first step to take in planning a preventive maintenance program is to: a) Lime b) Copper sulfate a) Replace all electric wiring c) Sulfuric acid b) Make an equipment inventory d) Methylene blue c) Replace all pump seals d) Repair all equipment which is not in operation Answer: a) Lime  Which of the following is the most important consideration in a  Most of the bacteria in sewage are: fire prevention program? a) Saprophytic 23 | P a g e  b) Dangerous  The standard capacity rating conditions for any refrigeration c) Parasitic compressor is: d) Pathogenic a) 5oF, 19.6 psig for the suction 86oF, 154.5 psig for the discharge Answer: a) Saprophytic b) 5oF, 9.6 psig for the suction 96oF, 154.5 psig for the discharge c) 10oF, 9.6 psig for the suction 96oF, 144.5 psig for the discharge d) 5oF, 19.6 psig for the suction 96oF, 134.5 psig for the discharge  One of the two types of non-material nuclear radiation is: a) 5oF, 19.6 psig for the suction 86oF, 154.5 psig for the discharge a) Gamma radiation b) Transmutation radiation  In accordance with the air pollution control code, no person shall c) Walton radiation cause or permit the emission of air contaminants from a boiler d) Betatron radiation with a capacity of 500 million BTU sulfur dioxide content of more than: Answer: a) Gamma radiation a) 300 parts per million by volume undiluted emissions  Which of the following is not a qualification for an applicant for measured at 15 percent excess air ME board examination: b) 200 parts per million by volume of undiluted emissions measured at 10 percent excess air a) A certified plant mechanic c) 200 parts per million by volume undiluted emissions b) At least 18 years old measured at 15 percent excess air c) A holder of BSME degree d) 300 per million by volume undiluted emissions measured at d) A citizen of the Philippines 10 percent excess air Answer: b) 200 parts per million by volume of undiluted Answer: a) A certified plant mechanic emissions measured at 10 percent excess air  A thermo hydraulic feed water regulator is used to regulate the flow of water to a drum type boiler. The amount of water input  Assume that one of your assistance was near the Freon 11 to the boiler is controlled in proportion to the: refrigeration system when a liquid Freon line ruptured. Some of the liquid Freon 11 has gotten into your assistant’s right eye. Of a) Boiler load the following actions, the one which you should not take is to: b) Setting of the feed pump relief valve c) Amount of water in the outer tube that flashes into steam a) Immediately call for an eye doctor specialist (medical doctor) d) Water level in the drum b) Gently and quickly rub the Freon 11 out of the eye c) Uses a boric-acid solution to clean out the Freon 11 from his Answer: d) Water level in the drum eye d) Wash the eye by gently blowing the Freon 11 out of his eye with air 24 | P a g e  Answer: b) Gently and quickly rub the Freon 11 out of the eye  In a refrigeration system, which of the following would cause a high suction pressure?  As compared to a power-driven triplex single-acting pump of a) Expansion valve not open wide enough the same size and operating at the same speed, a steam-driven b) Expansion valve open too wide duplex double-acting pump will: c) King valve not open wide enough d) Dirty dehydrator a) Pump more water per minute b) Give a more uniform discharge Answer: b) Expansion valve open too wide c) Have a higher first cost d) Be more economical to operate  In the deep well installing or operation, the difference between static water level and operating water level is called: Answer: a) Pump more water per minute a) Suction lift  It is a device commonly used to cool condenser water in Power b) drawdown and Refrigeration plants. The function of which is to reject heat c) priming level to the atmosphere by reducing the temperature of water d) clogging circulated through condenser or other heat rejection equipment. What is this device commonly called? Answer: b) drawdown a) Condenser  Which of the following is an characteristics of an impulse b) Cooler turbine? c) Cooling tower d) Evaporator a) Steam striking blades on angle b) No steam reaction to velocity Answer: c) Cooling tower c) Steam striking blades at zero angle d) Steam reversing direction  It is a type of dryer in which the gases of combustion pass through the spaces surrounding, or in other ways heating, the Answer: c) Steam striking blades at zero angle drying chamber, but the gases are not allowed in contact with  Gas produced by the combustion of fuel oil and cannot be found the material being dried. What is this dryer? in the flue gases is: a) Direct-heat type dryer a) Carbon dioxide b) Indirect-heat type dryer b) Hydrogen c) Steam-heated type dryer c) Oxygen d) Rotary Dryer d) Nitrogen Answer: b) Indirect-heat type dryer Answer: b) Hydrogen  Scale in boiler can: 25 | P a g e   Which of the following is other name for the liquid valve? a) Create low steam quality b) Cause foaming a) Freon valve c) Overheat blow off line b) shut off valve d) Inhibit circulation and heat transfer c) king valve d) Master valve Answer: d) Inhibit circulation and heat transfer Answer: c) king valve  The effectiveness of a body as a thermal radiator at a given temperature:  In accordance with recommended maintenance practice, thermostats used in a pneumatic temperature control system a) Absorptivity should be checked: b) Emissivity c) Conductivity a) Weekly d) Reflectivity b) Bi-monthly c) Monthly Answer: b) Emissivity d) Once a year  To protect adequately the engine bearings, what type and better Answer: d) Once a year arrangement of lubricating oil filter is most practical?  Of the following, the best method use to determine the moisture a) Full flow type filter installed between the lubricating oil pump level in a refrigeration system is to: and bearings b) Splash lubricating system in the crank case a) Weigh the driver after it has been in the system for a period of c) Duplex filter installed before the lubricating pump time d) Bypass filter with cleanable and replaceable elements b) Use a moisture indicator c) Visually check the sight glass for particles of corrosion Answer: a) Full flow type filter installed between the d) Test a sampler lubricating oil with phosphorus pentoxide lubricating oil pump and bearings Answer: b) Use a moisture indicator  When the expansion or compression of gas takes place without transfer of heat to or from the gas, the process is called:  A full-flow drier is usually recommended to be used in a a) Reversible hermetic refrigeration compressor system to keep the system dry b) Adiabatic and to: c) Polytrophic d) Isothermal a) Prevent the products of decomposition from getting into the evaporator in the event of motor burn-out Answer: b) Adiabatic b) Condense out liquid refrigerant during compressor off cycles and compressor start-up 26 | P a g e  c) Prevent the compressor unit form decreasing in capacity d) Condenses at a higher temperature d) Prevent the liquid from dumping into the compressor crank- case Answer: a) Contains more heat energy Answer: a) Prevent the products of decomposition from getting  Which of the following is not a characteristic of superheated into the evaporator in the event of motor burn-out steam? a) It contains no water droplets  You are supervising the installation of a steam-driven b) It causes severe erosion in pipes reciprocating pump. The pump’s air chamber is missing and you c) It may cause uneven heating of a product have to replace it with one with several salvaged ones. The d) It has a temperature greater than 165 oC salvaged air chamber selected should have a volume equal to, most nearly,: Answer: b) It causes severe erosion in pipes a) Half of the position displacement of the pump b) 1 ½ times the position displacement of the pump  Superheated steam at a pressure of 6 bar g: c) 2 times the piston displacement of the pump d) 2 ½ times the piston displacement of the pump a) Has a larger specific heat capacity than water b) Has a dryness fraction of 0.99 Answer: d) 2 ½ times the piston displacement of the pump c) Must not be used as a heat transfer medium d) Has a temperature greater than 165 oC Answer: d) Has a temperature greater than 165 oC  Economical partial-load operation of steam turbines is obtained by minimizing throttling losses. This is accomplished by:  Of the following, the main purpose of a sub-cooler in a a) Reducing the boiler pressure and temperature refrigerant piping system for a two-stage system is to: b) Throttling the steam flow into the uncontrolled set of nozzles c) Dividing the first-stage nozzles into several groups and a) Reduce the total power requirements and total heat rejection providing a steam control valve for each group to the second stage d) Controlling the fuel flow to the steam generator b) Reduce the total power requirements and return oil to the compressor Answer: c) Dividing the first-stage nozzles into several groups c) Improve the flow of evaporator gas per ton and increase the and providing a steam control valve for each group temperature d) Increase the heat rejection per ton and avoid system shutdown  How do you compare superheated steam to that of saturated steam at the same pressure? Answer: a) Reduce the total power requirements and total heat