Download Pipefitter Star Exam 2024-2025 Part 1 & 2. Real Questions and Correct, Verified Answers. and more Exams Engineering in PDF only on Docsity!
Pipefitter Star Exam 2024-2025 Part 1 & 2. Real
Questions and Correct, Verified Answers. Graded A
______ ______ are the dividing point between steam supply and condensate return piping. โ ANS Steam traps. ________ ________ permit the small amount of movement necessary to allow for pipe expansion which takes place when pipe is heated. โ ANS Swing joints _________ is added to copper to make _______. โ ANS Zinc added to copper to make brass 1 ton of refrigeration is equal to โ ANS 12000/btu/hr 4 main components in a refrigeration system โ ANS Compressor, Condenser, Evaporator, Metering device. 600WOG on a valve id plate stands for: - ANS Rated for 600lbs water, oil, or gas at ambient time A _______ is an arrangement of piping between the steam boiler's header and it's gravity-return piping. โ ANS Hartford Loop A bitmeal strip is composed of: - ANS 2 metals brazed together
A bushing is not a good replacement for a reducer because: - ANS offer more resistance to flow A compound gauge measures both ______ and ______ pressure. โ ANS Positive and Negative A cooling tower must have a _________ or be open-site โ ANS backflow preventer A diamond on an instrumentation loop diagram encloses information concerning - ANSset point A direct acting thermostat is used to โ ANS Increase the pressure when the temperature increases. A gallon of water occupies how many cubic feet โ ANS. A mixing valve has _______ inlets and _______outlets. โ ANS 2 and 1 A pop safety valve, that is set to open at 15 psi will close when the pressure is reduced to _______ psi. โ ANS 12 A single line drawing of a piping system represents: - ANS center of the pipe A solid that goes to a gas is called ______ - ANS Sublimation
Copper tube is designated as types: - ANSK, L, M, ACR, DWV Current polarity becomes an important factor with ______ power sources - ANSAll DC DCRP (electrode positive) is produced when the electrode is connected to the ______ terminal of the welding power - ANSPositive Device for collecting dust from the flue gas stream - ANSElectrostatic Precipitator Device that controls the pressure in a low pressure steam boiler - ANSPressuretrol Device which forma a water seal that prevents raw steam from entering and damaging pressure gauges: - ANSPigtail Eccentric reducer with hot water heating system Eccentric reducer with steam heating system - ANSFlat on top to prevent air buildup Flat on bottom to prevent condensate buildup Float and thermostatic trap rises to discharge - ANSCondensate Fluxes are classified into what three general groups? - ANSHighly Corrosive, Intermediate, Non-corrosive Formula for calculating step ahead in a parallel offset - ANS.414 x equal spread
Formula for Density - ANSmass/volume=density Four focus inspections OSHA compliance officers look for - ANSFall hazards, Electrical hazards, Caught in, Struck by Four principle functions of valves - ANSStart/Stop, Regulate/Throttle, Relief, Reduce Four types of check valves - ANSSwing, Lift, Vertical, and Ball check valves Four types of copper tube joints - ANSSoldered, Brazed, Flared, Compression Function of a metering device in refrigeration - ANSRegulates the flow of refrigerant Function of an evaporator - ANSAbsorb heat from the system Generates a small amount of voltage when heated - ANSThermocouple Harmful products of incomplete combustion - ANSCarbon Monoxide & Aldehydes Heat transfer surface that raises the steam temperature above corresponding saturation temperature - ANSSuperheater High pressure steam boilers operate at _____ to _____ psig - ANS15-5000 psig
In a hydronic heating system, units at the top of the system no heating are likely to be: - ANSAir bound In a piping installation allowing for expansion in two directions, who should the anchors and guides be positioned relative to eachother? - ANSGuide, anchor, guide In a refrigeration system, the _______ separates the high side from the low side - ANSmeter In a two pipe gravity return steam system, the device that prevents raw steam from entering the system is: - ANSSteam trap In order tor return condensate to a boiler the height of the water column needed to overcome the pressure drop in a two pipe gravity return system is: - ANS inches for each pound of pressure the boiler is producing In the expansion of liquids, we are concerned only with their increase in: - ANSVolume It is common for stainless steel to contain 18% _________ and 8%_________ - ANSChromium Nickel Length of pipe (drip connection) that is needed to overcome the pressure drop in a one pipe gravity return steam heating system and return condensate to the boiler - ANS28 inches
Low pressure steam boilers operate at ____ to ____ psig - ANS0-15 psig Magnetic field around a current carrying wire - ANSExists at all points long its length Main advantage of a fluidized bed boiler - ANSLow SO & NOx emissions Max height that a well pump can be installed above the water. - ANS25-27 feet Maximum recommended service temperature of a brazed joint - ANS350 F Measurement unit used to express rate of flow - ANSVelocity Metal which has a high iron content - ANSferrous Minimum safe working distance for overhead power lines - ANS10 feet Most common hanger type - ANSClevis Name 3 secondary refrigerants - ANSWater, Brine, Glycol Name of all segments of dies used for cutting threads - ANSChasers Name of the odorant in natural gas and propane - ANSMercaptan
Portion of the boiler which increaes the temperature of the steam so that it doesn't condense in the turbine - ANSReheater Pressure is ________ per unit of _______. - ANSforce per unit of area Pressure is - ANSforce per unit of area Quanting of heat involved to change a substance that can be measured with a thermometer - ANSSensible heat Reducing Tee's are sized according to: - ANSLarge end to smaller end to center Regulating or throttling flow is done with - ANSGlobe Soldered joints should never be used on systems above: - ANS250 degree F Specific gravity of a liquid can only be measured with a : - ANShydrometer Specific heat is defined as: - ANSamount of heat in BTU's required to change the temperature of 1 pound of substance 1 degree Steam condensate lines should be installed on - ANSRoller Hangers Steel melts at - ANS2588F
Superheated steam is ______ _______ and _____ with no change in ________ - ANSincreased heat and dry with no change in pressure T/F A cooling tower is more effective as compared to air cooled condensers in climates having low relative humidity - ANSTrue T/F A pressuretrol is used in connection with controls on a steam boiler - ANSTrue T/F It is essential to install a pressure reducing valve on the inlet cold water supply to a boiler water feeder. - ANSTrue T/F The OD on schedules std, xs, and xxs are the same for a given pipe size - ANSTrue T/F The specific heat of a substance is the ratio of it's heat capacity to that of water - ANSTrue T/F With the quantity of flow in gpm constant, the velocity of flow will increase with a decrease in pipe size. - ANSTrue The ________ absorbs heat while the __________ rejects heat - ANSevaporator absorbs, condensor rejects heat. The amount of heat in BTU required to change the temperature of one pound of a substance on degree F - ANSSpecific heat
The melting point of copper is ______ degrees F - ANS1085C or 1984F The most that a crane should be loaded is - ANS100% of the rated capacity. The pipe fitting which makes a 180 degree turn is called a: - ANSreturn fitting The pipe that connects the steam header to the boiler return connection is the - ANSequalizing line The process of changing from a solid to the liquid state is called _______, also known as _______ or _______. - ANSFusion Melting Liquification The proper way to extinguish a fire is to: - ANSPoint at the base and sweep the base with the extinguisher. The quantity of heat involved when any substance undergoes a change in temperature that can be measured is referred to as ________ _______. - ANSSensible heat The relief valve is sized to the ________ rating of a boiler - ANSGross Output The shape of a p-trap forms: - ANSa positive trap seal The size of ACR copper tube is designated by it's - ANSActual outside diameter
The specific density of mercury is _______ meaning it is..... - ANS13.6 meaning it is 13.6 times more dense than water. The specific heat of a substance is the ratio of it's heat capacity to that of _______. - ANSWater The steam flow into radiators in a one pipe gravity return steam heating system can be controlled by: - ANSInstalling an air vent with a different venting capacity The steam flow into radiators in a one pipe gravity return steam heating system can be controlled by: - ANSInstalling an air vent with different venting capacity The type of drawing that most closely resembles an object as the eye would see it is referred to as a ______ drawing. - ANSTrue isometric The type of drawing that views a building by looking directly at the front, top, and side is referred to as an _______ drawing. - ANSOrthographic Thermostatic traps are opened and closed by - ANSflexible bellows Three basic hitches which can be used for lifting with a sling - ANSStraight, Choker, Basket Three end finishes on pipe - ANSPESC (plain end squar cut) T&C (threaded and coupled) TBE (Threaded both ends)
Water is most dense at ________ degrees F - ANS39F Weakest part of a chain hoist - ANSLower Hook What are the three types of globe valves commonly found? - ANSy - pattern, angle, and straight What are two kinds of misalignment that must be checked for when installing pumps? - ANSParallel and angular alignment What causes water hammer? - ANSIncorrect valve operation What causes water to move in a hydronic system - ANSThe pump creates a differential in pressure that moves the water. What does the stamp Oxy-Med stand for on copper tubing? - ANSThe tubing has been cleaned for oxygen service. What is a device that changes a voltage signal to a current signal? - ANSE/I transducer What is hydronics? - ANSThe science of heat transfer using water What is installed after the isolation valve and before the trap union on a standard trap assembly? - ANSStrainer
What is likely to occur if the packing gland was adjusted too tightly? - ANSDifficulty in turning the wheel What is on the low side of the vapor compression cycle? - ANSThe evaporator What is the best gasket to use on a flanged joint on medium pressure steam? - ANSSpiral wound What is the best instrument for measuring vacuum? - ANSManometer What is the function of a compressor? - ANSCreate flow in the system What is the function of a condeser - ANSReject heat from the refrigerant What is the gear ratio for an 8" primary gear and a 24" secondary gear? - ANS3 to 1 What is the maximum working pressure of the average hot water boiler? - ANS30psi What is the minimum safe clearance between cranes and energized power lines operating at 50 kV or below? - ANS10 feet What is the primary purpose of a flux? - ANSTo chemically clean the metal surfaces to be soldered or brazed.
What type of pump is normally used as a feed water pump? - ANScentrifugal What type of sensor is directly in the process stream - ANSImmersion What type of valve should be used to bypass a control valve? - ANSGlobe valve What type of valve should be used to bypass a control valve? - ANSGlobe valve What would be the result of an incorrectly installed orifice plate? - ANSErratic Readings When steam is superheated its: - ANStemperature is increased with no increase in pressure Where is a bourdon tube found? - ANSIn a pressure gauge Where must the expansion tank be located in a gravity hot water system? - ANSAbove the convector. Where should the high pressure condensate be piped to before entering the receiver? - ANSFlash Tank Where should the pressure enter a globe valve - ANSDepends on the desired action if the disc or plug becomes detach from stem (fail open or fail closed) Which component in a closed control loop is the primary element? - ANSSensor
Which hitch can support the most weight? - ANSBasket Hitch Which of the copper types has the smallest wall thickness - ANSdwv Which of the elements of wire rope aid in absorbing shock loads? - ANSThe core Which one of the following is typically a final control element? - ANSValve Which one of the following measures and takes action - ANSController Which type of orifice plate is designed to measure flow of liquids containing solids
- ANSSegmental Which way should the bevel face an orifice plate? - ANSDownstream Why can the flux be omitted in a brazed joint? - ANSThe flux is in the filler material Why should the angle between the leg of a swing and the load never be less than 30 degrees? - ANSMore stress loads are applied on the sling Work is defined as - ANSforce times distance .414 x equal spread - ANSFormula to calculate the step ahead in a parallel offset
