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24 Cards in this Set
- Front
- Back
What type of pipe is used on gas pipe?
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Black pipe
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What should be used on the gas pipe fittings to prevent leaks?
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Piping compound
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What are three components that must be installed in the gas pipe before hooking into the gas valve?
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1. Union
2. Drip leg 3. Shut–off |
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What is the purpose of a drip leg on the gas line? |
Prevents debris and moisture from entering gas valve
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How long and how much pressure should be held in the gas pipe to make sure they are not leaking?
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3 psig for 10 min
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If a gas line is sized too small, this will create a _______ ____ to the gas valve.
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Pressure drop
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What type of pipe should be used to run flues?
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B–type
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Why should running flues horizontally be avoided?
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Condensation build up
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How much of a rise should be in flue pipe run horizontally?
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1/4 inch per foot
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When a B type pipe goes through a ceiling or floor how much clearance should the pipe have between it and combustible materials?
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1 to 3 inches
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Single wall pipe should have ______ clearance from combustible material.
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6 inch
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When hooking two flues to a common flue, is the smaller flue hooked in above or below the bigger flue?
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Above
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Should a connector vent be placed as high or as low on the common vent as possible?
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High
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What are the names of the PVC pipes that are used for the high efficiency flue?
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Intake and Exhast
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Why must a mid–efficient furnace in a confined furnace room be vented?
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Combustion
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Where should the two vents be located in a furnace room to provide proper venting?
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Floor and Ceiling
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What must be used to properly charge a central air conditioner?
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Charging chart
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Where will the charging chart be located on a central air conditioner?
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On back or cover of control panel
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What method is used with the charging chart to charge a system with a fixed orifice?
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Super–heat
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What method is used with a TXV valve?
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Subcooling
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What are the design temperatures and humidity used on central air conditioners?
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75 Degrees and 50%
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When checking a charge it is found that the actually super–heat is 8 ํ lower than what the charging chart recommends, would refrigerant be added or removed?
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Removed
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What does it mean to balance the duct system?
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Stop uneven Temps and have proper C.F.M.s
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How is the duct system adjusted to get the proper air flow to the rooms?
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Dampers
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