Manufacturing technologies and joining methods of metallic thin-walled pipes for use in high pressure cooling systems

Abstract

Small diameter thin-walled pipes, typically with a diameter less than 20 mm and a ratio of outer diameter to wall thickness is 20 or above, have increasingly become a key value adding factor for a number of industries including medical applications, electronics and chemical industries. In high-energy physics experiments, thin-walled pipes are needed in tracking detector cooling systems where the mass of all components needs to be minimised for physics measurement reasons. The pipework must reliably withstand the cooling fluid operation pressures (of up to 100 bar), but must also be able to be reliably and easily joined within the cooling system. Suitable standard and/or commercial solutions combining the needed low mass and reliable high-pressure operation are poorly available. The following review of literature compares the various techniques that exist for the manufacture and joining of thin-walled pipes, both well-established techniques and novel methods which have potential to increase the use of thin-walled pipes within industrial cooling systems. Gaps in knowledge have been identified, along with further research directions. Operational challenges and key considerations which have to be identified when designing a system which uses thin-walled pipes are also discussed.

Brazing of Copper Pipes for Heat Pump and Refrigeration Applications

“…However, this process also has some disadvantages, such as being able to cause corrosion; the joints must be small; and the need for careful preparation of the joint to obtain satisfactory results. The joint is highly dependent on the joint clearance or distance between parts and the optimal distance depends on the filler material and joint design [18]. To guarantee a good brazed joint, both components to be connected must be properly cleaned and protected from oxidation, either through the use of flux or through a controlled atmosphere [19,20].…”

Microstructures and mechanical properties of cold rolled pipes with increased small deformation

“…Research is conducted with the aim of improving produc tion technologies to ensure the regulated norms and standards of requirements for pipe accuracy [2] and microstructure [3]. Foreign researchers are also engaged in similar issues [4,5].…”