What is copper Tube?
Copper is a part of many applications over the past and continues to be a valuable one, even today. Primarily it is involved in systems that convey water across. From residential complexes to offices and industrial areas, this metal has many users. The tubing material is a part of HVAC systems. HVAC or Heating, ventilation, and air conditioning is a system that offers acceptable quality indoor air as well as thermal comfort. The tubing is available in two tempers, which are soft and hard. Drawing tubes makes them hard and rigid. To soften the material is tempered by annealing. The production of a softened pipe is much more expensive than a hard, non-annealed variety. Softer copper tubes are a popular choice for refrigerant lines. Their applications include both split-system air conditioners as well as heat pumps. Contrary to the former temper type, hardened or rigid temper tubes are less expensive and are popular as waterlines. Methods such as roll grooved, solder or sweat, compression, or crimped/pressed could be apt in forming a connection between the tube and fitting.
Since the metal is hard and does not bend, the use of fittings like an elbow is routine around obstacles or corners. Methods such as solder or sweat, roll grooved, compression, or crimped/pressed are used to forge a connection between a tube and a fitting.
Tubes supplied according to ASTM specification are 99% copper. And these tubes are available in six grades. They consist of type K, type L, type M, DWV, ACR as well as Medical gas. The standard ASTM size, designate the fore-mentioned grades. Every grade signifies a set of different sizes with varying wall thicknesses. For instance, the walls of type K are thicker in comparison to type L, while type M is thicker than that of type L for any produced diameter.
Difference between Seamless & welded copper tubing.
The production of a welded tubing is from either a metal sheet or a strip. The welded variety is free from filler metal and has a seam on the longitudinal section. The formation of a tube via extrusion is known as a seamless. Unlike its welded counterpart, the molten metal passes through a billet. Hence, there is no visible seam. However, with an increase in the surface treatment or polishing processes, the weld seam could be minimized to a large degree. Some types of surface treatment work towards reducing the seam to such an extent - that it is not visible to the naked eye.
Another point of differentiation between the two types is the cost factor. Typically, a welded tubing is cheaper to produce in comparison to a seamless kind. The standard specification for a welded cu tubing is ASTM B 447, whereas the specification for a seamless one includes - ASTM B 88 or ASTM B 75 or ASTM B 68, depending on the finishing performed on the tube.
For instance, bright annealed tubes adhere to specification ASTM B 68. Whereas, specification ASTM B 75 covers regular seamless tubes, and lastly, water tubes of this variety are covered by specification ASTM B 88.
A shortcoming associated with a seamless tube is that the production with regards to length is limited. Its counterpart, however, does not have length restrictions. Though using a weld version is discouraged in environments where they are likely to become prone to hydrogen embrittlement. Hydrogen embrittlement causes stress, which in turn leads to the tube cracking.