UNIT 7 Flashcards
The joining of two pieces of copper tubing of the same diameter by expanding or stretching the end of one piece to fit over the other, so that they can be soldered or brazed
Swaging
Produces flame temperatures in the range of 3600°F slightly higher than butane
Propane
Consist of a liquid line and insulated suction line. That may be pre-charged with refrigerant, and sealed at both ends.
Line set
Plastic pipe used for hot or cold water supplies that can withstand temperatures up to 180°F at 100 psig. Can be joined by glue or threaded joint.
CPVC
Joining two pieces of copper tubing, utilizing filler material that melt at temperatures under 842°F usually in the 361°F to 500°F range
Soldering
Prevent oxidation from forming on the surface of pipes being joined, and in the filler materials themselves. Also helps facilitate the flow of filler material into the joint.
Flux
A mixture of fuels that produce flame temperatures of about 3730°F
MAPP gas
Used to remove burrs after cutting tubing or steel pipe
Reamer
Threads designed to form a metal to metal seal with or without sealant by using thread deformation
National pipe taper
Measure from the outer diameter instead of the inner diameter
ACR tubing
The oxygen regulator pressure is set to 10 psig when the valve on the torch head is cracked open. What is the acetylene pressure regulator set to when the valve on the torch head is cracked open?
5 psig
True or false
Bending springs can be either inside or outside of tubing
True
True or false
45% silver is considered soft solder
False
True or false
A carbonizing flame is used for most brazing operations
False
True or false
Never use a cigarette lighter or match to light a torch
True
Flux can overheat, and become saturated with oxides
True
True or false
The proper solder to use for a copper to steel joint is 45% silver
True
True or false
Plastic pipe does not need to be reamed after cutting
False
True or false
Do not apply pipe dope closer than two threads from the end of the pipe
True
True or false
Teflon tape should/can be used on compression fittings for a leak free seal
False
True or false
PE pipe is used for water, gas and irrigation systems
True
True or false
Compression fittings are not intended for refrigerant, piping circuits
True
PE pipe is attached to fittings using hose clamps. How are the hose clamp positioned
Screws of the clamp on opposite sides of the pipe
Steel pipe should have_________ perfect threads and_______ imperfect threads
7 perfect and 2/3 imperfect threads
When soldering flux should be applied to…….
Male part of the joint only
Pipe threads when used on pipe that will contain liquid or vapor under pressure……..
All of the above
A tube that is over flared will cause what to happen when the flare nut is tightened?
It will cause a leak
When soldering without using a nitrogen purge, the oxide formed within the tubing, will eventually travel throughout the system and collect where?
Metering device, filter dryer compressor oil
What is the purpose of removing any excess flux after soldering?
To prevent acid buildup on tubing/piping
What can be used to clean tubing that will be used on a hermetic compressor?
All of the above
When adjusting the flame for a propane/MAPP gas torch, where should the flame be in relation to the torch tip?
Outside of the torch head
You are changing out a compressor and need to solder the suction and discharge lines onto the new compressor. The solder on the older compressor tubing is gold in color. What type of solder was used for the joint?
45% silver solder or higher
Is flux required to solder the lines onto the new compressor in number 32
Yes
Moisture+ acid+ oil=
Sludge
Do azeotrope refrigerants have a temperature glide or do they behave like a single compound refrigerant?
No temperature glide and acts like single compound refrigerants.
How many BTUs in 8 kW of electrical power?
3413 BTUs= 1kW—-3413BTUs x 8kW= 27,304 BTUs
What components make up HFC refrigerants?
Hydrogen, Fluorine, Carbon
Lines of constant quality on an enthalpy diagram give you the percentage of________as you go from left to right on the diagram.
Vapor
Specific volume is measured in_____________
Cubic feet/lb
The density of aluminum is 171 lb/ft3. What is its specific volume?
1/171lb/ft3= 0.00584795 ft3/lb
