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LWC Copper Tubes used in the manufaturing of
Heat Exchangers
Cooling Coils
Condensor Coils
Evaporator Coils
Copper Tubing Components
Copper Fittings
Header Pipes
Handicrafts
Level Wound Copper Tubes (LWC): Quality, Use and Applications
What is a level wound copper tube?
A level wound coil (LWC) is soft copper tube wound in neat, even layers, like thread on a spool. Each turn sits beside the one before it, and the layers are stacked evenly. This is different from a loose coil, where the tube lies in a random tangle.
The even winding gives three advantages:
The coil is compact and stable for storage and transport.
The tube pays out smoothly, so it does not kink or flatten while being uncoiled.
It works well with automatic uncoiling and straightening machines in factories.
LWC is made from soft (annealed) copper, so it bends easily, and it is cut to length after straightening. It is sold in a wide range of outer diameters and wall thicknesses.
What makes a high quality LWC tube
When comparing suppliers, look at these points:
Pure, correct copper. Refrigeration tube is normally made from phosphorus-deoxidised copper, around 99.9 % pure. Low-grade or recycled mixed scrap causes cracks, pinholes and brazing problems.
Accurate wall thickness and diameter. Wall thickness decides how much pressure the tube can handle. A thin spot is a weak spot. Good tube has an even wall, round shape and tight tolerances, so fittings and flares seal properly.
Clean inside. Rolling oil, dust or moisture left inside the tube can block capillary tubes, damage the compressor and contaminate the refrigerant. Good tube is cleaned, dried and sealed at the ends, often with a dry nitrogen charge.
Correct softness. The tube must be fully annealed so it bends without cracking, but not so soft that it flattens easily.
Leak and quality testing. Reputable makers test every coil for leaks or defects, for example with eddy current testing, and check pressure strength samples. Ask for a test certificate or inspection report.
Clean surface and good winding. There should be no deep scratches, dents or green or black stains, and the layers should be even and tight.
Standards and marking. Look for compliance with recognised standards such as ASTM B280 (tubes for air conditioning and refrigeration) or the equivalent Indian or European standards, plus clear labelling of size, thickness and batch.
Tip: in your product tables the working and burst pressure depend on wall thickness. For higher pressure refrigerants such as R410A, choose a thicker wall.
How LWC tube is used
Select the outer diameter and wall thickness for the job.
Uncoil and straighten the tube, by hand for small jobs or with a machine in a factory.
Cut to length with a proper tube cutter, then remove burrs from the ends.
Bend with a bending tool to avoid kinks and flattening.
Join with flare fittings or by brazing. While brazing, flow dry nitrogen through the tube, otherwise oxide scale forms inside.
Test by pressurising with nitrogen to check for leaks, then evacuate with a vacuum pump before charging refrigerant.
Where LWC tubes are used
Air conditioners: split and window units, for the lines between the indoor and outdoor units and for coil connections.
Refrigerators, freezers and deep freezers: for condensers, evaporators and connecting lines.
Cold rooms and cold storage: for long refrigerant lines.
Chillers and heat pumps: in heating and cooling systems.
HVAC and commercial refrigeration: supermarket display cases, bottle coolers and ice machines.
Other uses: automatic coil-processing lines, and some water and gas applications where the standard allows it.
Why copper
Copper conducts heat very well, resists corrosion, bends easily, brazes reliably and is fully recyclable. These qualities keep it the first choice for refrigerant lines, even though cost is higher than some alternatives.
Advice before you buy
Ask the supplier for the test certificate, the standard it complies with, and a sample coil. Cut the sample, then check the wall thickness, look inside for oil and dirt, and test a bend. Do this before placing a large order.