Hydronics

Hydronics

Multiple ChoiceIdentify the letter of the choice that best completes the statement or answers the question.

1. Which of the following statements is correct when referring to large refrigerant or nitrogen tanks?a. The protective cap must be on when the tank is not in use.b. Safety goggles or glasses must be worn when moving the tank.c. Large tanks should not be carried, they should be secured to an

approved cart.d. All of the above are correct.

ANSWER: DPOINTS: 0 / 1FEEDBACK:

2. When it is necessary to perform electrical work in an area that has a damp or wet floor, which of the following can be done to minimize the chance of electrical shock?a. Place a rubber mat on the floor.b. Use a wooden ladder.c. Wear insulated boots and gloves.d. All of the above


3. When using a torch to braze a fitting, the technician should use the proper size ____, wear ____, and always have a ____ nearby.a. copper pipe, insulated boots, fire extinguisherb. torch tip, insulated boots, protective fire shieldc. torch tip, safety glasses, fire extinguisherd. acetylene tank, safety glasses, bucket of water

ANSWER: CPOINTS: 0 / 1FEEDBACK:

4. An example of a pressure vessel is ____.a. a small ship containing refrigerant cylindersb. the compressor in a refrigeration unitc. a cylinder containing refrigerant

d. a portable dolly


5. An R-22 cylinder containing enough refrigerant to have liquid refrigerant in it, is in a truck with a temperature of 120°F. What would be the psig pressure in the cylinder?a. 255.7 psigb. 259.9 psigc. 267.0 psigd. 271.5 psig

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6. A cylinder with 1,500 sq. in. of internal surface contains R-22 and is in a service truck body at 120°F. What is the total outward force of the refrigerant against the inner wall of the cylinder in tons of pressure?a. 202.64b. 226.61c. 194.92d. 145.71


7. A fusible plug is a metal fitting that has a hole drilled through it and the hole is filled with ____.a. material with a low melting pointb. plasticc. copper fused with brassd. a metal alloy that will burn when overheated

ANSWER: APOINTS: 0 / 1FEEDBACK:

8. When transferring refrigerants from a cylinder to a refrigeration system or any other container, you should always wear ____.a. goggles with side shields and glovesb. heavy protective clothingc. rubber gloves

d. industrial steel-toed shoes and an insulated cap


9. Before using a voltmeter, always ____.a. Zero the ohms adjustment.b. Touch the two leads together to insure continuity.c. Set the range selector to a setting higher than the voltage you expect

to read.d. Turn off the power.


10. A double insulated drill ____.a. has two ground wires to insure proper groundingb. generally has a plastic case with the electrical connections and motor

insulated within the toolc. is used with a three- to two-prong adapterd. has rechargeable batteries


11. In electrical circuits, the grounding wire is typically ____.a. blackb. redc. green or bared. white


12. The reason for using zone valves on a hydronic heating system is to ____.a. allow different areas of the structure to maintain different

temperaturesb. reduce the chance of a water leakc. prevent unused parts of the house from getting warm, and wasting

energyd. both a and c


13. Air in a hydronic system can cause ____.a. reduced water circulationb. increased efficiencyc. corrosiond. both a and c


14. A pressure relief valve is set at 30 psig. The valve is constantly opening and flooding the floor. What should the technician do?a. Increase the set point of the relief valve to 40 psig.b. Find the cause of overfiring.c. Put a bucket under the valve.d. Both a and c are correct.


15. A series loop hydronic system is not desirable for use in a large residence because ____.a. all of the heated water will flow to all roomsb. some rooms will overheat before other rooms are warmc. they are extremely noisyd. both a and b


16. A limit control on a hot water boiler is needed to ____.a. regulate the amount of water to each section of baseboardb. regulate the water in the supply line to the boilerc. balance the water flow rate in the piping systemd. protect the boiler against excessive water temperatures


17. The pressure relief valve ____.a. regulates the pressure of the water in the supply lineb. is set to relieve the pressure in the boiler below the maximum design

pressure of the boilerc. shuts the boiler off if the water temperature gets too highd. relieves the pressure in the expansion tank


18. The expansion tank provides a means of removing the air from the system as well as ____.a. provides a space for excess water from the supply sourceb. provides water for the domestic hot water coilc. provides a space for the water expansion and contraction with water

temperature changesd. all of the above


19. An expansion joint is a device used to ____.a. prevent damage between boiler sectionsb. connect the expansion tank into the systemc. allow for expansion and contraction of the loop piping with water

temperature changesd. connect the manual vent into the system


20. In a series loop hydronic heating piping system, ____.a. the heated water flows in the same direction in parallel pipesb. the heated water flows in the opposite direction in parallel pipesc. part of the heated water is directed to each terminal unitd. all the heated water flows through all the terminal units


21. A column of water one foot high exerts a pressure of ____.a. 0.396 psig

b. 0.407 psigc. 0.433 psigd. 0.496 psig


22. Air in the hot water circulating system will cause ____.a. corrosionb. noisec. flow blockaged. all of the above


True/FalseIndicate whether the sentence or statement is true or false.

23. When working in a machine room, safety glasses should not be worn because they can fog up and impede your eyesight.

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24. If you are a refrigeration technician, a warm coat and gloves should be in your truck, even in the middle of the summer.

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25. Aluminum ladders are safe to use around electrical equipment as long as they have insulation pads on the bottom of the rungs.


26. It is possible that your hand would suffer frostbite if it comes in contact with liquid R-22 when accidentally releasing refrigerant into the atmosphere (an illegal procedure).


27. As long as the torch is kept moving below the level of the liquid refrigerant in the cylinder so as not to create a hotspot, it is OK to heat the cylinder in this manner.


28. To insure proper operation of an oxygen cylinder regulator, make sure no oil residue is present.


29. A necessary safety practice for a technician is to keep a padlock with only one key in the tool box.


30. When an oil or gas boiler is used, the water chamber is divided into smaller compartments to increase the surface area on which the heat can act.


31. If a parallel hydronic system is installed, it may be necessary to bleed air from each of the parallel circuits.


32. Expansion tanks must always be bled from the top until all of the air is removed from it.

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FEEDBACK:

33. It is possible for a hydronic system with many zones to operate with one circulating pump.


34. Hydronic heat circulators are centrifugal pumps.


35. In a series loop, the water going through the last terminal unit will be the same temperature as the water through the first terminal unit.


36. The only place a bleed valve is needed is on top of the boiler.


37. A tankless domestic water system provides hot water from a coil in the boiler.


CompletionComplete each sentence or statement.

38. Oil must never be used around an ____________________ cylinder.

RESPONSE:ANSWER: oxygenPOINTS: 0 / 1

39. The easiest way to move equipment across a roof is to use

________________________________________.

RESPONSE:ANSWER: rollers and plywood for a basePOINTS: 0 / 1

40. Power tools that are not double insulated must have three-prong plugs to ensure that the tool is properly ____________________.

RESPONSE:ANSWER: groundedPOINTS: 0 / 1

41. Refrigerants from a refrigeration system that has a burned out motor-compressor assembly can be dangerous because it could contain a high concentration of ____________________.

RESPONSE:ANSWER: acidPOINTS: 0 / 1

42. Hydronic heating can refer to both ____________________ and ____________________.

RESPONSE:ANSWER: hot water, steamPOINTS: 0 / 1

43. The device that will shut down a boiler if the water temperature gets too high is called a ____________________.

RESPONSE:ANSWER: limit controlPOINTS: 0 / 1

44. The most popular way of heating using a hot water system is by the use of _________________________ on the outer walls of the area.

RESPONSE:ANSWER: finned-type baseboardPOINTS: 0 / 1

45. The zone control valves are controlled by _________________________.

RESPONSE:ANSWER: zone thermostats

POINTS: 0 / 1

46. The main source of air into a hydronic system is the ____________________.

RESPONSE:ANSWER: supply waterPOINTS: 0 / 1

47. Hot water boiler limit controls are usually set at ____________________°F.

RESPONSE:ANSWER: 200POINTS: 0 / 1

48. Circulators in hydronic systems use impellers with vanes between side panels. These are called ____________________ impellers.

RESPONSE:ANSWER: closedPOINTS: 0 / 1

49. The material used to make circular impellers is ____________________.

RESPONSE:ANSWER: bronzePOINTS: 0 / 1

50. An automatic air bleed valve controls the airflow out of the system by means of a ____________________.

RESPONSE:ANSWER: float valve

Hydronics

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