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Plumbing IP > A Little Bit of Everything! > Flashcards

A Little Bit of Everything! Flashcards

1
Q

The traps at the base of a 10 storey soil-or-waste stack are continuously being blown out. What would cause this to occur?

a. An oversized vent stack
b. An oversized stack vent
c. An undersized vent stack
d. An undersized stack vent

A

c. An undersized vent stack

Note: a stack vent protects the top four floors. A vent stack protects the bottom four floors. The role of each is to limit the pressure differential in the stack. An undersized stack would not be able to limit that differential

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2
Q

What are the obvious signs of pump cavitation?

A

Noise and vibration.

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3
Q

Which piping material may be used to replace a damaged galvanized water line in a historic building?

A

Galvanized pipe.
Note: the answer to this question is in the appendix of the NPC in Tables A.2.2.5, 2.2.6 and 2.2.7. There are notes at the bottom of the table which indicate that galvanized piping may be used to replace water lines in a historic building

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4
Q

You are asked to go and service a hot water tank. The problem is that the tank seems to “rumble” when you fire it up. What could the issue be?

a. Water pressure is above 80 psi
b. Excessive condensation in the B- vent
c. Faulty temperature and relief valve
d. Hardness scale buildup on the bottom of the tank

A

d. Hardness scale buildup on the bottom of the tank

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5
Q

How do you change the top element in a hot water tank?

A

Shut off power, shut off water, drain tank, change element, close drain, turn on water, turn on power

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6
Q

A urinal tank continues to flush. What component could be faulty?

A

The siphon.

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7
Q

A galvanized conventional galvanized expansion tank is waterlogged. How would you fix this problem?

A

Close the isolation valve, open the air inlet valve, open the drain valve, allow water to drain and air to enter, close the drain valve, close the air inlet valve, and open the isolation valve

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8
Q

There is leak in the waterpipe between the city main and the property line. Which valve needs to be closed in order to fix the leak?

A

Corporation stop.

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9
Q

How is the flush affected if the bypass orifice is partially blocked on a flush valve?

A

Longer flush.

Note: if the bypass orifice is blocked it will take longer for water to accumulate in the upper chamber of the flush valve. This causes a longer flush as it’s the pressure of the water in the upper chamber which forces the flush valve closed.

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10
Q

How would the flush be affected if the diaphragm in a flush valve was ruptured?

A

Continuous flush.

If the diaphragm in a flush valve was ruptured it would fail to separate the water
above the diaphragm and below the diaphragm. It’s the water pressure above the
diaphragm which closes the valve and if there is no difference between the pressure in
the upper chamber and the lower chamber the valve will not close.

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11
Q

To replace a faulty spring (coupler) on a dry-rotor circulator:

A

Disconnect power, loosen set screw, remove bolts and pull motor.

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12
Q

If a compression style stop is found to be leaking and after changing the washer
is still leaking, what may be the cause?

A

Worn or damaged seat.

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13
Q

How is the domestic water temperature maintained in the upper floors of a six
storey building?

A

Recirculation line.

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14
Q

How is the volume of flow to a urinal flush tank

controlled?

A

Needle valve (or metering valve).

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15
Q

What is the problem if the water tastes salty from a water softening system?

A

The rinse cycle was too short.

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16
Q

Where is the best location to take a water sample from a pumped well system?

A

The closest outlet to the pump.

Note: this is due to the fact that taking a sample as close to the source as possible is
the best indicator of water quality in the well.

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17
Q

If the jet assembly in a deep well jet pump system must be lowered what must
also be done?

A

Re-adjust the control valve.

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18
Q

If you are sent to work on a boiler pump in a factory and you find the pump
disconnect locked out, who can remove the lock?

A

Worker who owns the lock.

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19
Q

What procedure should be followed to eliminate vibration created from a base
mounted pump?

A

Install the pump on an inertia base and spring isolators.

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20
Q

What is sugaring?

A

Sugaring is when oxygen is allowed to get to the weld and it deforms
the weld on the inside causing what looks like a honeycomb or sugar
like substance to form on the weld.

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21
Q

How do you convert U.S. gallons/min to fixture units?

A

Take the number of U.S. gallons and multiply by 2.

Ex: 120 U.S. gallons x 2= 240 fixture units.

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22
Q

How do you convert Imperial gallons/min to fixture units?

A

Convert Imperial gallons to U.S. gallons and multiply by 2.

Ex: 100 Imperial gallons x 1.2= 120 U.S. gallons x 2= 240 fixture units.

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23
Q

A copper water service pipe is to be removed and replaced with a polyethylene
(PE) water service. What components must be added to the system?

A

Check valve, provision for expansion.

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24
Q

What is the required torque and sequence for installing mechanical joint
couplings 4 inch and under?

A

Tighten evenly to 60 inch-pounds.

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25
Q

What is the required torque and sequence for installing mechanical joint
couplings 6 inch and over?

A

Tighten evenly to 80 inch-pounds.

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26
Q

What is a schreader valve? How would it cause an expansion tank on a shallow well pump to cycle?

A 
A schreader valve is similar to
the valve used on a bike tire in order
to fill the tire with air. One reason an
expansion tank might be cycling is
that the schreader valve is faulty and
has released all the air from the
expansion tank.
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27
Q

When is a sump pump used? When is a submersible pump used?

A

Sump pump used for drainage applications.

Submersible pump used for potable water applications.

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28
Q

What is the normal percentage oxygen level in the air? What is considered a low
level?

A

21 percent is normal.

19.5 percent or less is low.

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29
Q

When using oxyfuel what type of protection are you required to wear?

A

5 faceshield.

30
Q

A flushometer is running continuously and needs to be serviced. What is the first
step the plumber should do when servicing an automatic flush valve?

A

Close the control stop and then flush the valve.

31
Q

What is radon gas?

A

Radon is a gas formed by the breakdown of uranium, a natural radioactive
material found in all soil and rock. Long-term exposure to radon is the 2nd
leading cause of lung cancer after smoking and the leading cause of lung
cancer for people who have never smoked.

32
Q

What methods can be used to prevent Radon from entering a dwelling?

A

• Active sub-slab depressurization (Active soil depressurization) –
most common
• Sump hole depressurization
• Drainage system depressurization
• Active sub-membrane depressurization (crawl space)
• Sealing major entry routes
• Increasing mechanical ventilation

33
Q

What type of trap do bidets have?

A

Exposed trap.

34
Q

To what temperature is water cooled for a drinking fountain?

A

10 degrees Celsius.

35
Q

Flaring tools provide two different flare angles for two different applications. What are they?

A

37° automotive/aircraft or 45° pipe trades.

36
Q

What is the most likely cause if a diaphragm flush valve flushes too long or fails to shut off?

A

Bypass hole dirty or plugged.

37
Q

What is the most likely cause if a piston flush valve flushes too long or fails to shut off?

A

Piston not seated properly.

Bypass orifice clogged.

38
Q

Why would you need to protect water service piping by means of a check valve?

A

If the water service piping material is rated for cold-water service only, care must be taken to protect it from expanded hot water.

39
Q

What is the maximum working pressure of a low-pressure water boiler? A low-pressure steam boiler?

A 
30 psig (water).
15 psig (steam).
40
Q

What is the maximum operating temperature of a low-temperature boiler?

A

121 °C (250 °F).

41
Q

What is a pyrometer?

A

A device used to measure high temperatures.

42
Q

What is the stack effect?

A

The impulse of a heated gas to rise in a vertical passage.

43
Q

What is thermal mass?

A

Any material used to store heat energy or the affinity for heat energy.

44
Q

What is an Airtrol tank fitting? What is its purpose?

A

A device installed on the bottom of a cushion tank. It simultaneously allows expanded and contracted water to flow to and from the tank and discourages the escape or withdrawal of air from the tank.

45
Q

What does boiler trim refer to?

A

Piping on or near the boiler that is used for safety, limit and operating controls, gauges and water columns.

46
Q

What is a compound gauge?

A

A bourdon tube pressure gauge used to indicate pressure or vacuum inches of Hg.

47
Q

What is convection? conduction? radiation?

A

Convection - transfer of heat through a solid.
Conduction - transfer of heat through a liquid or gas.
Radiation - transfer of heat from one object to another through an intervening space which does not get heated.

48
Q

What is a downfeed or overhead system?

A

A heating system in which the heating mains are above the level of the heating units being served.

49
Q

What is a monoflow or venturi tee? Where is it used?

A

Used to create an obstruction in a pipeline and a drawing effect on the downstream side. Used on one-pipe forced hot water heating systems.

50
Q

What is head pressure? What is feet of head?

A

Head pressure is the pressure available at the outlet side of a pump; expressed in feet of head.
Feed of head is the height of a column of water that can be supported by a pump against standard atmospheric pressure.

51
Q

What is an example of a low-mass boiler? High-mass boiler?

A

Low-mass boiler - copper and some steel-finned water tube boiler; small volume of water.
High-mass boiler - cast iron sectional and fire tube boilers; have large quantity of water.

52
Q

What type of hot water boiler can be used to directly heat domestic water?

A

Copper water tube.

53
Q

What can cause coil damage in a low-mass boiler?

A

Low or not flow through the heat exchanger.

54
Q

What mandatory device is required on a coil type boiler over 400,000 Btuh?

A

Flow switch.

55
Q

What is the purpose of a balancing valve?

A

To adjust flow rates to each heat transfer unit.

56
Q

What is the purpose of a wild loop?

A

Prevents the pump from deadheading.

57
Q

What is the minimum return water temperature for a conventional boiler?

A

140 °F.

58
Q

What device is specifically installed to prevent gravity circulation?

A

Flow check valve.

59
Q

What is the normal operating aquastat set point for a non-condensing boiler?

A

180 °F.

60
Q

How do you control heat output to a baseboard convector installed in a series?

A

Adjust dampers.

61
Q

Which device switches power to a motorized zone valve motor causing it to open?

A

Thermostat.

62
Q

What is pump cavitation?

A

Cavitation occurs when the liquid in a pump turns to a
vapor at low pressure. It occurs because there is not enough pressure at the suction end of the pump, or insufficient Net Positive Suction Head available (NPSHa).
When cavitation takes place, air bubbles are created at
low pressure. As the liquid passes from the suction side of the impeller to the delivery side, the bubbles implode.
This creates a shockwave that hits the impeller and creates pump vibration and mechanical damage, possibly leading to complete failure of the pump at some stage.

63
Q

When does pump cavitation happen?

A

When there is low pressure at the inlet.

64
Q

What is a 3-piece wet rotor pump?

A

It is a sealed pump that does not require lubrication. The wet-rotor pump combines the motor, the shaft, and the impeller in a single assembly housed in a chamber filled with system fluid.

65
Q

What is a positive displacement pump?

A

A positive displacement (PD) pump is a general name for a pump type that does not have impellers, but rather relies on rotating or reciprocating parts to directly push the liquid in an enclosed volume, until enough pressure is built up to move the liquid into the discharge system.

66
Q

What is the correct order to tighten bolts on a flange?

A

The first pass, lightly tighten the first bolt then move directly across or 180 degrees for the second bolt, then move 1/4 turn around the circle or 90 degrees for the third bolt and directly across for the fourth. Continue this sequence until all bolts are tightened.

67
Q

Solder having alloys that melt below 840 °F (449 °C) are known as?

A

Soft solders.

68
Q

When specifying a soft solder, what content is always mentioned first?

A

Tin.

69
Q

At what temperature does 50-50 solder start to melt and flow freely at?

A

360 °F and 415 °F.

70
Q

For service temperatures up to 250 °F (121 °C) where high strength is required, what solder should be used?

A

95-5.

71
Q

At what temperature does 95-5 solder start to melt and flow freely at?

A

450 °F and 465 °F.

72
Q

Between what temperatures do Sil-Fos solders melt at?

A

1185 °F to 1300 °F.

Plumbing IP (6 decks)

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