Should stainless steel coil heat exchangers use welded tubes or seamless tubes?
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I have recently come into contact with stainless steel coil heat exchangers. Some people say that welded stainless steel tubes are sufficient for low-pressure applications, while seamless stainless steel tubes are used only in high-pressure situations. I would like to hear everyone’s opinions and suggestions on how to decide whether to use welded or seamless tubes I know it must be seamless pipes; the key question is by how much more expensive are seamless pipes compared to welded pipes? Is it very difficult to manufacture welded pipes?
Seamless pipe. Currently, due to the economic situation, the prices of seamless pipes are relatively low. Seamless pipes also carry certain risks, and using welded pipes increases those risks even further.
What are the risks of seamless pipes? Do seamless pipes have joints?
Seamed pipes can be used for pressures below 10 MPa, while seamless pipes are used for pressures above 10 MPa.
Considering costs, welded pipes are generally used, right? Also, from a manufacturing perspective, welded pipes can ensure an adequate length :)
There are no joints; because, in the case of sheets similar to welded pipes, uneven wall thicknesses or material defects in the seamless pipes themselves can also lead to leaks
In recent years, the technology for seamless pipes has become increasingly mature; it is possible to wind the pipe directly online, and hydrostatic testing is carried out after the product is completed. There are already many successful cases from clients.
From a technical perspective, when choosing between seamless and welded stainless steel pipes, the main considerations are the designed pressure-bearing capacity of the pipe as well as its actual pressure-bearing capacity； Additionally, the operational lifespan and efficiency of the equipment are also factors that need to be considered ； Overall ； Compared to welded stainless steel pipes, seamless ones have a higher pressure resistance; moreover, welded pipes are prone to corrosion at the weld areas ； This is the advantage of seamless pipes ； On the other hand, most seamless heat exchange tubes in China are manufactured through cold forming. During this production process, due to limitations in equipment or manufacturing techniques, some manufacturers have technical defects such as uneven wall thickness or heat treatment that does not meet requirements; these issues can also affect the service life of the seamless tubes. This situation is caused by fierce competition in the domestic market, and choosing a reliable manufacturer can largely eliminate such risks ； Seamless pipes are much better than seamless pipes in terms of precision control and roundness. From an economic perspective, seamless pipes are not necessarily more expensive than welded pipes; the cost depends on the specific materials, dimensions, and the processing techniques chosen ； Generally speaking, for thin-walled pipes, the production cost is lower when they have seams rather than being seamless ； The production cost of thick-walled pipes without seams is lower than that of those with seams ； Additionally, some materials are not suitable for welding or are too hard; in such cases, processing seamless tubes might be more convenient. This is just my personal opinion – feel free to add your insights.
It’s easy to choose; when high pressure is required, seamless pipes are necessary. The pressure required for use is low, so a pressure test on the welded pipe can be conducted first. This isn’t a multiple-choice question with no options.
Wuxi Yiming Metal, a professional supplier of heat exchange tubes
When the working pressure and temperature are not high, and there is no risk of stress corrosion in the working medium, welded pipes can be considered an option; they are sufficient for the requirements, cost-effective, and economical.