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71 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Type _______ copper is used only in plumbing. Type_______ copper is used in plumbing and ACR applications Type _______ copper is used in underground ACR and plumbing applications |
Type M plumbing Type L ACR and plumbing Type K underground ACR and plumbing |
M - matter L - K - kollapse |
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What is the main difference between plumbing, ACR, and underground rated copper? |
Wall thickness |
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What is the typical difference in wall thickness between ACR copper and the other two types? |
Typically about 1/8” difference in wall thickness |
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List for different methods for joining copper tubing |
Soldering Brazing Flaring Crimping |
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Flaring is the process of expanding the end of copper tubing into a __________ shape at a _________ degree angle |
Funnel 45 deg |
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To flare the end of copper tubing you would need to clamp the tube into a __________________, and set the _____________ with the ____________ shaped compressor over the end to press the flares |
Die block Yoke Cone shaped compressor |
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Brazing is a process by which two copper ends are joined using a ________________, at high temperatures over _______________ |
Filler metal 1300 deg f ??? Double check this |
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Brazing forms a ______________ bond between the two metals being joined |
Metallurgic |
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True or false? Brazing is the process of fussing two metals together with a filler material |
False A metallurgic bond is formed. The base metals are not fused |
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What is the temperature range for brazing ACR copper? |
1100-1600 deg f (1205-1550) |
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Silver soldering @ 45% silver starts to melt at _________ and flows freely at ____________ |
Starts to melt at 1120 deg f Flows freely at 1145 |
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Si fos at 15 % silver should contain __________ copper and _____________ phosphorus |
80% copper 5% phosphorus No iron or steel |
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15% si fos should begin to melt at _________ and flow freely at ___________ deg f |
Melt at 1185 Flows freely at 1300 deg f |
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A _________________ stage regulator and _________ meter should be used when low pressure purging while brazing at approximately _______ PSIG or approximately ___________ CFH |
Second stage regulator Flow meter 50 PSIG 3-6 CFH |
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Purging with nitrogen will displace _____________ in the lines and prevent ______________ and __________________ |
Oxygen Oxidation Scale formation |
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Portable oxyacetylene kits typically use what size tanks? |
MC acetylene tank (10 cu ft) R oxygen tank (20 cu ft) |
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What ratio of acetylene to oxygen should be attained while brazing? What type of flame should be used? |
1:1 Neutral flame (no acetylene feather) |
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What PSIG should be considered the maximum when brazing? |
5 PSIG |
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What are two total sizes for air acetylene torches? |
MC tank (10 cu ft) B tank (40 cu ft) |
Mctank is mini gas tank B tank is bus tank (big) R tank is Air tank |
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Overtightened Tube cutter cuts can cause copper to become ________________________ and hacksaws can create _______________________ |
Oblong Excessive burrs, chips, filings. |
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Soldering temperatures also known as _________ soldering typically utilizes temperatures in the _________ to __________ range. Or under temps of ____________ |
361-500 deg f Under 842 deg f |
Solder is colder. You Can solder all day! (Think 842 backwards 24 hours or an 8 hour day) You can solder all year! (361-500 think 365 days in a year) |
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What is 95/5 solder used for? And what are its components? |
Potable water and high pressure 95% tin 5% antimony |
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What is 50/50 solder used for and what are its components? |
Medium pressures and temperatures 50% tin 50 % lead |
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Brazing is typically referred to as _________________________ or _______________________ and typically utilizes a temperature range from ______________ to _____________ |
Hard soldering Silver brazing 1205-1550 |
Think higher temps so you can only braze for half a day (or 12 hours ….1205 degrees) also think 12:05 after lunch to 15:50 (3:50) is the hottest part of the day and you need to stop working at ten to 4:00 to put away your tools. |
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Brazing utilizes temperatures above ___________ |
842 deg f |
All day! 24 hours OR 8 hours |
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Copper used for __________ and ___________ is measured by its inside tubing and is referred to as ______________ sized tubing |
Heating Plumbing Nominal |
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Hard drawn tubing is available in ____________ diameters than soft drawn copper. |
Larger |
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Soft copper can become ___________________ if overworked. But can be ___________________ |
Work hardened Annealed |
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Soft copper can become ___________________ if overworked. But can be ___________________ |
Work hardened Annealed |
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When re-softening or _____________ soft copper, a _______________ flame should be used |
Annealing Flared flame (over 1 ft at a time) |
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Typically hard copper used in the heating and plumbing industry has a diameter of ________. |
1/8 inch |
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A 5/8 nominal diameter pipe has an internal diameter of ______ and an external diameter of _______ |
5/8 internal 3/4 external |
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5/8 “ Type L copper will have an internal diameter of ______ and an external diameter of _______ |
Internal ? (Look up I think there’s a chart) External 5/8 |
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What are the three types of oxy/acetylene flames and their attributes? |
Carburizing = too much acetylene Neutral = 1:1 ratio Oxidizing = too much oxygen which oxidizes the copper and prevents flow of filler metal |
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At what pressure should copper ACR lines be pressure tested? |
200-800 PSIG |
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At what rate should nitrogen flow when brazing? And when purging before brazing? |
Purging = 20-50 CFH Brazing 3-5 CFH |
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What should the inlet pressure be set to on a Hilmor flow meter? |
50 psi |
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True or false? Solder can be used to connect ACR piping. |
True! If the right filler metal is used |
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What does sweating refer to when brazing/soldering? |
Sweating is another term for soldering. It refers to joining copper lines usually water but sometimes ACR at temps lower than 842 deg F |
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When soldering what is the purpose of flux? |
Flux helps prevent oxidation and aids the flow of solder |
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True or false Bubbling flux is an indicator of high solder temperatures |
False Flux bubbles as base metals begin to approach correct working temperatures. Bubbling stabilizes as proper temperatures are reached |
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Generally what amount of solder should be used in a joint? |
Length of solder equivalent to the pipe diameter |
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What pressure should be used for pressure testing? |
Refer to data plates (evaporator and condenser) |
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List all standard safety protocols for brazing |
- Ensure proper ventilation - transport and store all tanks according to manufacturer Rec’s - wear PPE (gloves, safety glasses, - Ensure proper ventilation - protect surrounding areas (ie use fire cloth) - keep fire extinguisher nearby and don’t handle hot copper |
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On two stage tank regulators, what does each gauge refer to? |
Right is tank pressure Left is outlet/working pressure |
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List three methods of leak detection |
- micro foam - electronic leak detector (nitrogen with trace gas can be used) - ultrasonic |
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True or false A carburizing flame can be used for brazing ACR fittings |
True If set up properly, a carburizing flame can remove oxides from the weld and produce a clean joint |
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True or false? A neutral flame prodeuces the hottest temperatures and is recommended for joining ACR fittings |
False An oxidizing flame is hotter |
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Type K copper is indicated with ____________ colour writing, type L is indicated with ____________, and type M is indicated with ____________. |
Type K: green Type L: blue Type M: red |
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Thickness of type M copper typically hovers around _________ wall thickness. Whereas Type L is _________ and tie K is ____________ |
M = under 1/32 (0.028 for 5/8) L = under 1/16 (0.040 for 5/8) K = under 1/16 (0.049 for 5/8) |
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On an oxyacetylene rig, the red hose is attached to the acetylene regulator with _____________ handed threads and the green hose is attached to the oxygen regulator with ____________ handed threads. |
Red acetylene left Green oxygen right |
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Flux contains _________________% water and so it must be used sparingly (only on the __________ side of the fitting). Another negative affect that is possible when using flux is _______________ which can lead to improper flow of filler metal as the flux becomes _______________________. Flux must be cleaned after as it is _________________. |
15-35% water Male Overheating Saturated with oxides Corrosive |
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How does flux facilitate a better weld? |
It absorbs the oxides which helps prevent the oxides from forming within the weld. Oxides prevent a good consistent bond and weaken the joint. Flux helps facilitate the flow of material into the joint. |
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List two reasons why flux may not be required for brazing. |
- Many brazing rods contain phosphorus which has a self fluxing characteristic. - the higher temperatures used in brazing/ carbonizing flame are able to burn off any oxides and clean a joint in the process of welding |
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What is the main reason 410A systems require nitrogen purge brazing over other systems? |
They contain ester based lubricants which are more likely to separate oxides from the inside of the piping |
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When can you get away with low temp solder in a refrigeration system? |
If using 95/5. Just don’t use it close to a compressor on the high side as it won’t hold up to the abuse (pressure/vibrations) Instead use a low temp solder with silver and high strength properties |
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What are 90% copper brazing rods used for? |
Vibration free areas in an ACR system |
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What brazing filler materials require flux? |
Those contain 45% silver |
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What must be done differently when joining copper to steel? |
Expansion ratios: copper expands quicker than steel. Joints must be assembled with this in mind |
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Does silver increase or decrease the flow point of the filler material? |
Increase working temperatures |
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What material should be avoided when joining steel to copper? What would you use when connecting a copper suction line to a steel compressor? |
Avoid phosphorus containing material as it will form phosphides which create a brittle weld. In this scenario, use 45% silver containing material. Higher temperature and increased strength. |
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What are some considerations for brazing large diameter hard drawn tubing? |
Strength: use silver Low temp is better to maintain the temper of the copper |
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What is the temperature difference between an air acetylene and oxy acetylene torch and what are the typical target temperatures for each? |
4200 deg f air acetylene with target temperature of 2700, 5600 deg f oxy acetylene with target temperature of 4700 |
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At what temperature does copper melt? |
2000 deg f |
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What does MAPP stand for? |
Methyl-acetylene propadiene propane |
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What does MAPP stand for? |
Methyl-acetylene propadiene propane |
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Compare the flame temperatures of propane and MAPP gas? |
Propane: 4000 deg f MAPP: 5300 deg f |
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The portion of a compression fitting that tightens against the tubing to create a leak free seal is the: |
Union |
A) coupling B) union C) compression nut D) ring or ferrule |
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All ACR /gas threaded steel piping must be _______________ |
Tapered |
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The taper on a threaded steel pipe is at an angle of __________ degrees or __________ “ per ft or ____________” per inch |
60 degrees 3/4” per ft 1/16” per inch |
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What is maximum pressure loss and gain in a system? |
30 psi is maximum loss 60 psi is maximum gain |
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