Mechanical Engineering Chapter 7 Piping Equipment And Systems Overview Piping Equipment And Systems Deal With

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CHAPTER 7

PIPING EQUIPMENT AND SYSTEMS

OVERVIEW

Piping equipment and systems deal with the hardware and components of piping systems.

Similar to the preceding chapter on air-handling systems, Chapter 7 goes into detail that

is best understood after exposure to the more basic materials in Chapters 3, 4, and 5,

which covers overall systems.

Piping Equipment and Systems begins with basic review of engineering principles of

fluid flow, then describes HVAC applications including fundamentals of pump

CHAPTER 7

PIPING EQUIPMENT AND SYSTEMS

QUESTIONS AND ANSWERS

7.1 What factors are considered in selecting pipe size for fluid flow applications?

7.2 What feature most differentiates turbine pumps from centrifugal pumps?

How are turbine pumps applied in HVAC systems?

7.3 What feature most differentiates positive displacement pumps from

centrifugal pumps? How are positive displacement pumps applied in HVAC

systems?

7.4 For a given water piping system, a pressure of 50 ft of head is required to

produce 30 gpm water flow. How much pressure will be required to flow 60

gpm?

7.5 Compare differences in flow and head developed for two identical pumps

operating in parallel vs. operating in series.

comparison with steel?

7.7 What factors limit maximum velocities in piping systems? Minimum

velocities?

7.8 What are the main differences in characteristics of calcium silicate, fiberglass,

and foam rubber insulation, which would affect their applications?

7.9 What is the functional difference between a control valve and a balance

valve?

7.10 Under what circumstances would three-way control valves be used rather

than two-way control valves, despite their higher expense?

7.11 What is the purpose of a check valve?

7.12 What are limitations and disadvantages of open expansion tanks for hot water

systems?

7.13 What are the advantages and disadvantages of expansion loops in comparison

with slip joints for thermal expansion compensation?

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Expansion loops are generally less expensive, but require care in engineering and

allowance for space for lateral movement.

7.14 What provisions are recommended for air control in hydronic piping?

7.15 What provisions are recommended for condensate control in steam piping?

7.16 Why is reverse return piping system more desirable than direct return?

7.17 Why is closed loop system better than open loop system?

7.18 Is water cooling tower piping system an open or closed loop system?

7.19 One psi is equal to 2.31 feet of water. ( True ) ( False )

7.20 Calculate the WHP of a water piping system with flow rate of 100 gpm and 30

feet head.

7.21 What BHP shall be required if the pump selected has an efficiency of 75%

operating at this condition?

7.22 What are the two types of fluid exchangers?

7.23 Which heat exchanger type is ideal for low temperature differential?

7.24 Grooved pipe mechanical joints can be used for steel pipe only. ( True ) (

7.25 The advantage of grooved pipe mechanical joints is its extremely strong

coupling.

( True ) ( False )

7.26 Soldered joints are used for type K copper. ( True ) ( False )

7.27 What is the equivalent straight pipe length of a 2″ screwed globe valve? A 2″

gate valve?

7.28 Why is it necessary to have air venting in a hot water system?

7.29 What is the latent heat of steam at 10.3 psig?

7.30 The total heat of steam at 50 psig (include sensible heat of condensate at 200

q

F

and latent heat of vapor) is _____. (From Table 7-6).

7.31 What is the absolute pressure (psia) at 60.3 psig?

7.32 What is the temperature of saturated steam at 65 psia?

7.33 What refrigerants have the least Ozone depletion potential?

7.34 What commercial refrigerant has the least global warming potential?

7.35 How many pounds of refrigerant flow per minute are needed to produce one

ton of refrigeration?

7.36 What are advantages of using district-heating plants instead of individual

building heating systems?

7.37 What are the main advantages and disadvantages of distributing steam at

higher pressures?

7.38 The contractor offers a fair cost credit for deleting isolation valves from the

new heating system he is constructing for you. Why should you insist that he

install the valves?

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7.39 Why is it important to repair leaky steam traps as soon as possible?