Products for HVACR
Meta-Braze™ Silver/ Copper Phosphorus Brazing Alloys
Meta-Braze™ silver/ copper phosphorus brazing alloys are designed to braze copper to copper. The phosphorus within the filler metals gives them a self-fluxing characteristic on copper components so in this situation there is no need to use separate brazing flux.
Which Brazing Alloy Rod is Suitable for HVACR Tube and Pipe Joints?
Silver / copper phosphorus rods such Meta-Braze™179, Meta-Braze™ 182, Meta-Braze™ 279, Meta-Braze™ 281, Meta-Braze™ 283 and Meta-Braze™ 284 are all suitable for flux free brazing of copper pipes and tubes in HVACR applications. So which alloy is best?
Selection of the optimum brazing alloy depends on the type of brazed joint and the conditions it will see in service. Points to consider when choosing which to use are: the cost of the brazing alloy which is affected by the percentage of silver in it; the flow of the alloy when molten – too fluid an alloy (such as Meta-Braze™ 283) may run off the joint; the ductility of the brazing alloy, if the joint is going to be manipulated after brazing or will be subject to vibration in service a more ductile alloy such as Meta-Braze™ 281 should be selected.
Balancing these factors, the cost, the flow and the ductility for an application will inform the choice of which product to select. For more information consult VBC Group.
Brazing of K65 Copper Tube for CO₂ Refrigerant
Advanced refrigeration systems such as those found in supermarkets are increasingly adopting environmentally friendly refrigerants such as R744 (CO₂ grade) require piping systems approved for operating pressures up to 120 bar.
Copper tubing such as K65 tubes and the corresponding fittings can be used to make up a copper-based system for high-pressure applications. Studies have shown that most of the silver copper phos brazing alloys will make a sound joint on K65 copper. However other factors such as cost, working temperature of the molten alloy, ductility and alloy flow when molten need to be considered.
Considering all these factors VBC Group recommends Meta-Braze™ 281 brazing alloy for brazing K65 copper pipes and tubular fittings. This alloy has a good combination of properties at an affordable cost.