1

February 11, 2014

• Aluminum Refrigeration Tubing

1

2 ALUMINUM REFRIGERATION PIPING Presented by: Garry L. Rose P.E.

REFLOK North America

ASHRAE – Minnesota Chapter

February 11, 2014

3

Aluminum Refrigeration Piping

Aluminum Tubing with MAFs* compared to traditionally brazed Copper

*MAF - Mechanically Attached Fitting

4

Topics

• International Mechanical Code

• ASHRAE 15

• ASME Standard B31.5

• COPPER – ASTM B280

• ALUMINUM – ASTM B210

• Installation of Copper Refrigeration Piping

• Installation of Aluminum Refrigeration Piping

• VRV Systems

• Advantages of Aluminum Refrigeration Piping

• Cautions of Aluminum Refrigeration Piping

5

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

6

ASTM Standard B31.5 Copper – ASTM B280

• C12200 – H58, O50

• Seamless

• Cleaned

• Capped

• Eddy Current Tested

• Marked

• Type L

• Blue Stripe

• Country of Origin

• OD, Wall Thickness

Aluminum - ASTM B210

• 6061-T4

• Seamless

• Cleaned

• Capped

• Eddy Current Tested

• Marked

• “Seamless”

• Alloy, Temper

• Country of Origin

• OD, Wall Thickness

7

Installation of Copper Piping

• VRV Pipe Kit

8

Installation of Aluminum Piping

• VRV Pipe Kit

9

VRV Systems

• 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

10

Installation Comparison

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.

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

11

Maximum WP per ASME B31.5

12

Advantages of Aluminum Refrigeration Piping

• 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.

13

Cautions when using Aluminum Refrigeration Piping • 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.**

14

Aluminum VRV Installation

• Y-Branch Piping

14

15

Copper VRV Installation

• Y-Branch Piping

15

16

Mechanically Attached Fittings • Refrigeration Service Valves

16