Aluminum Refrigeration Piping

February 11, 2014
• Aluminum Refrigeration Tubing
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ASHRAE – Minnesota Chapter
February 11, 2014
ALUMINUM REFRIGERATION PIPING
Presented by: Garry L. Rose P.E.
REFLOK North America
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Aluminum
Refrigeration Piping
Aluminum Tubing with MAFs* compared to
traditionally brazed Copper
*MAF - Mechanically Attached Fitting
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Topics
• International Mechanical Code
• ASHRAE 15
• ASME Standard B31.5
• COPPER – ASTM B280
• ALUMINUM – ASTM B210
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Installation of Copper Refrigeration Piping
Installation of Aluminum Refrigeration Piping
VRV Systems
Advantages of Aluminum Refrigeration Piping
Cautions of Aluminum Refrigeration Piping
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Code Requirements for
Refrigeration Piping
•International Building Code
• International Mechanical Code
• ASHRAE 15
• ASME B31.5 – Refrigeration Piping and Heat
Transfer Components
• Copper - ASTM B280
• Aluminum - ASTM B210
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ASTM Standard B31.5
Copper – ASTM B280
Aluminum - ASTM B210
• C12200 – H58, O50
• Seamless
• Cleaned
• Capped
• Eddy Current Tested
• Marked
• 6061-T4
• Seamless
• Cleaned
• Capped
• Eddy Current Tested
• Marked
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Type L
Blue Stripe
Country of Origin
OD, Wall Thickness
“Seamless”
Alloy, Temper
Country of Origin
OD, Wall Thickness
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Installation of Copper Piping
• VRV Pipe Kit
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Installation of Aluminum
Piping
• VRV Pipe Kit
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VRV Systems
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Typically R-410A
Design Working Pressure: 580 psi
Lots of Refrigeration Tubing
All lines must be insulated
Liquid, Hot Gas, Suction
Hot Gas Line typically must account for expansion/contraction
Multiple Evaporators
Cleanliness is of utmost importance
POE or PVE Oils must have DRY system
• Triple Evacuate to less than 100 microns
• No filter driers in refrigeration piping
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Installation Comparison
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Copper Tubing
Brazing is required for 400
series refrigerants.
Drawn copper working
pressure must be de-rated to
annealed ratings.
Annealed copper Type L meets
580 psi working pressure thru
1/2” only.
Nitrogen purge during brazing
is required.
May require hot work permits.
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Aluminum Tubing with MAFs
MAFs have 600 psi working
pressure.
No heat is required, so neither
copper or aluminum working
pressures are required to be
de-rated.
No nitrogen purge required.
No hot work permits required.
1/3 weight of copper
Stable pricing compared to
copper
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Maximum WP per ASME
B31.5
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Advantages of Aluminum
Refrigeration Piping
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Aluminum is VERY corrosion resistant.
Slightly better fatigue life than copper.
6061-T4 is field bendable. (no fittings required).
Hanger spacing can be increased for aluminum tubing.
Aluminum is 1/3 the weight of copper.
Using Mechanically Attached Fittings, no heat is required.
• Therefore, no acetylene, no brazing rod, no nitrogen purge during
assembly, no hot work permits,
• No de-rate of working pressure due to annealing of tube.
• System remains clean during installation.
• All joints to same factory standard.
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Cautions when using
Aluminum Refrigeration Piping
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Must use di-electric when connecting to dissimilar metals.
Must isolate piping from hangers.
Coefficient of linear expansion is 20% greater than copper
Do not flare aluminum tube, then connect to brass flare fitting.
(Potential for galvanic corrosion)
• **Aluminum Tube for commercial refrigerant piping is NOT a
mature industry. There is a lot of chance for wrong material
selection, that does not meet ASME code requirements. Make
sure the tubing used is “SEAMLESS”, as defined by ASME. Make
sure the alloy is 3003 or 6061.**
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Aluminum VRV Installation
• Y-Branch Piping
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Copper VRV Installation
• Y-Branch Piping
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Mechanically Attached
Fittings
• Refrigeration Service Valves
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