All four classes of tubing can be used with the capillary solder system. The choice of tubing will depend on the nature of the work to be performed. SABS 460 Class 1, 2 & 3 all have excellent bending qualities. There are various bending machines on the market and those with inner and outer formers make the best bends. The cheaper hand benders and springs do not perform satisfactorily on the above mentioned class of tubes.
Half hard tubes bent by hand should have a radius of at least 6 times the outside diameter of the tube and machine bent tubes should have a radius of not less than 3 times the outside diameter of the tube. Any deviation from the above figures could cause a restriction in the tube producing turbulent flow and the possibility of erosion corrosion. Note: Damaged and worn bending equipment will result in a failure.
Copper tubing, due to the very smooth bore, maintains excellent flow characteristics as there is less chance of furring than with traditional materials.
Because of copper tube’s excellent internal corrosion resistance, tube bores remain smooth and internal diameters constant, thus eliminating the need to account for bore reduction or roughening when computing friction losses as with steel piping.
Copper’s light weight facilitates shipment, fabrication and installation. When comparing steel pipe systems, weight reductions of up to 50% are afforded by copper systems. This is significant in terms of hanger requirements and dead loads imposed on supporting structural elements.
Copper is compatible with all types of piping. It is accepted practice to join copper tubing to galvanized piping provided that the copper is downstream from the galvanized pipe. Certain corrosion problems may be experienced under specific conditions if the copper tube is connected upstream.
When cutting copper tube with tubing cutters or a hacksaw, care should be taken to produce a square end and to remove the burr produced. This will remove the possibility of turbulent flow which could promote erosion corrosion.