3-22.3-23.3-24.3-25.3-26.The globe valve gets its namefrom the globular shape of itsbody, a shape that is unique tothis valve.1.True2.FalseApproximately how far must thehandwheel of a globe valve beturned toward the closed positionafter the valve has been fullyopened?1.1/4 turn2.1/2 turn3.3/4 turn4.7/8 turnWhat type of flow control valvemakes the most suitable throttlevalve?1.Gate2.Plug3.Globe4.NeedleLearning Objective:Relate theoperation, functions,requirements, and constructioncharacteristics of pressurecontrol devices to fluid powersystems.Relief valves are used for whichof the following functions?1.To maintain pressures above apredetermined level2.To maintain fluid flow belowa predetermined rate3.To prevent pressure fromrising above a predeterminedlevel4.To prevent thermal expansionof the fluidsIf a fluid power system uses twoor more relief valves, they mustall be the same size.1.True2.False3-27.Chatter in a relief valve is theresult of1.rapid opening and closing ofthe valve as it ‘hunts- aboveand below a set pressure2.too much difference betweenopening and closing pressuresof the valve3.concurrent operation of thesmall relief valve and themain relief valve4.improper seating of the valveelementREFER TO FIGURE 6-13 IN YOUR TEXTBOOK INANSWERING QUESTIONS 3-28 AND 3-29CONCERNING THE OPERATION OF A COMPOUNDRELIEF VALVE.3-28.When the system pressureincreases above the pressure towhich the valve is set, the mainvalve opens1.independently of the pilotvalve2.only after the systempressure increases to morethan can be relieved by thepilot valve3.concurrently with the pilotvalve4.every time the pilot valveopens but at a predeterminedtime interval afterward3-29. After the main valve has relievedthe system and when pressurereturns to normal, what doespilot valve do?1.2.3.4.It remains open until afterthe main valve closesIt closes simultaneously the main valveIt closes first and allowspressure to equalize aboveand below the main pistonIt closes first and causespressure above the mainpiston to force the mainvalve closedthewith18
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