Soldering and Brazing Flashcards
T or F - Coper is a non-ferrous metal
True
T or F - ACR copper tubing does not need to be kept plugged or capped.
False
T or F - Brass is an elemant listed on the Periodic Tables
False
The outside diameter of copper tube types K, L and M are the same
True
Cup-joint drainage fittings may be used on pressure piping systems
False
Solder and brazed joints are not recommended for soft temper copper tube
False
Brass is an alloy of Copper and Zinc
True
Never secure a gas cylinder to a conduit carrying
electric current
The suggested shade number for filter lenses for torch brazing is
4
The suggested shade number for filter lenses for torch soldering is
2
The most common type joints for connecting copper tube are?
soldered and brazed
What is the max service temperature for copper tube when soldered joints are used?
250 F
The flow of a liquid when it is drawn into a small space between wet surfaces is?
capillary action
A material or substance made up of two or more elements, at least one of which is a metal, is a/an?
Compound
The size of ACR copper tube is designated by?
Actual outside diameter
How is the size of copper water tube designated
by its nominal inside diameter
Which of the 3 types of copper water tube has the heaviest wall thickness?
K
DWV copper wall thickness is __ than Type M
less than
If you ran out of 5/8” OD ACR fittings on a job what size water tube fitting could you use?
1/2”
Why is it recommended that flux be applied to copper as soon as possible after cleaning?
prevent oxidation
After fittings are cleaned and fluxed, they should be assembled and soldered:
asap
Which torch valve should be closed first, oxygen or acetylene, when a flashback occurs?
oxygen
Overheating a joint when brazing a wrought copper fitting causes
oxidation and distortion of the joint
Soldering is done at what temperature?
under 840 degrees
Brazing is done at what temperature?
above 840 degrees
True or False - Brazing has a higher melting/pasty range than soldering
True
What are the 2 classes of brazing filler metals suitable for joining copper?
BAg and BCuP
Solders have a ____ instead of a melting point
melting range
Name one disadvantage of using tin-silver solders
high cost
What are the primary advantages of tine-silver solder
easy to use and filleting ability
Brazing filler metal is used to designate a brazing alloy which has a melting temp exceeding
1100 degrees F
Define Alloy
a substance made up of 2 or more metals
The 2 classes of brazing filler metals differ in their
melting, fluxing and flowing characteristics
The most widely used solders for making solders joints on copper tube are ___ and ___
50/50 tin lead and 95/5 tin antimony
Why are new lead free solder considered easy to work with?
It has a low initial melting point and wide melting range
Of the 2 classes of brazing filler metal which one is more economical and why?
BCuP - because it has lower silver content
When using solder-flux what 3 rules should be observed
- Dont depend on the flux to clean the tube.
- wire solder must be added to the joint to fill the voids
- the paste mixture must be thoroughly stirred before using
True or False - heat has no effect on the rate of oxidation of metal
false
True or False - Brazing fluxes are generally stronger than soldering fluxes
true
____ or ___ on the high pressure side of an oxygen cylinder can cause an explosion
Oil, Grease
Name 4 types of copper tube joints
Soldered
Brazed
Flared
Compression
What is the difference between soldering and brazing?
Temperature -
Soldering: below 840 degree
Brazing: above 840 degrees
Is it possible to weld copper tube?
Yes - butt welded
When soldering, is it necessary to use a non-ferrous filler metal which has a melting point below that of the base metal?
Yes
What is the max service temperature for copper tube when brazed joints are used?
350 degrees F
The most common method of joining copper tube is with the use of ___ fittings
cup joint
T or F - Flared joints are often used for connecting underground lines
True
Name the types of Copper tube
K,L,M & DWV
What are the 3 general classified groups for fluxes?
- Highly corrosive
- Intermediate
- Non-corrosive
What are the ingredients of the most common fluxes for soldered joints in copper tube?
zinc chloride and/or ammonium chloride
Which solder melts at the higher temperature, 50-50 or 95-5
95-5
True or False - Joint preparations for soldering and brazing are two different procedures?
False
What are the 3 most common sources of heat used for soldering or brazing copper tube joints
- Air propane
- Air acetylene
- Oxyacetylene
An Air-acetylene flame produces a ______ amount of heat than an air-propane flame
Greater
An excess of acetylene in an oxyacetylene flame will give a ___ flame
carburizing
When making a soldered joint using cast fittings, name 2 things which could cause the fitting to crack
- wiping
2. quenching
Flux may be omitted when joining copper tube to wrought copper fittings with ___ alloys because they are self-fluxing on copper.
BCuP series
When heated, 95/5 tin-antimony solder begins to melt at a temperature of ___ºF and becomes a liquid at 464ºF.
452
T or F - When brazing with a copper tube, wrought copper fittings, and BCuP brazing filler metal, fluxing is optional.
T
Unsoldered areas may be the result of improper cleaning, fluxing, or heating if the surface is ________________.
dry
A perfectly soldered joint will show the entire cup area of the fitting to be completely covered with ________________, which will have a grayish surface
solder
When brazing copper tube to wrought copper fittings, a(n) ________________ filler metal may be successfully used without the use of flux
BCuP
T or F - Where corrosion is a factor, cadmium-free filler metals of the BCuP classification that contain nickel are best suited.
F
T or F - Brazed joints, with cup-joint fittings, are used where greater strength is required or where system operating temperatures are as high as 250ºF.
F
T or F - Because of the thinness of its wall, copper tube is not normally threaded.
T
T or F - It is not possible to use the tube of one manufacturer with the fittings of another manufacturer without any installation problems.
F
T or F - Copper-to-copper joints shall be made using a copper-phosphorus brazing filler metal without flux.
T
When a non-ferrous filler metal is applied, but is not distributed in the joint by capillary action, it is called _______.
braze- welding
T or F - Since the high-temperature would destroy the color marking of a tube if applied, hard temper tube is not color marked.
F
T or F - Since the high-temperature would destroy the color marking of a tube if applied, hard temper tube is not color marked.
False
Types K, L and M tube are designated by standard (nominal) sizes ___.
1/4” to 12”
Type K copper tube is color coded ________________ to distinguish it from other types of copper tube.
green
True or False - It is not possible to use the tube of one manufacturer with the fittings of another manufacturer without any installation problems.
F
