Issues regarding the inlet of heat exchangers designed per ASME standards
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An exchanger designed in accordance with ASME standards is being imported from abroad; according to Chinese standards, it falls under the category of pressure vessels. The medium used is highly hazardous. The foreign designer used welded tubes for the heat exchange tubes, but per Chinese standards, welded tubes are not allowed – seamless tubes must be used instead. There are two issues that present difficulties: 1. The foreign manufacturer holds a manufacturing license issued by China’s Quality Inspection Bureau. Will this equipment be able to be registered successfully upon inspection? At least from the perspective of the heat exchange tubes, welded tubes do not meet China’s pressure vessel standards. 2. Assuming that this equipment is successfully registered and put into use in China, if the owner wishes to replace the piping system in the future and opt for manufacturers in China to produce it, the owner hopes to obtain a product that is identical, both in terms of material and design standards ； From a national standard perspective, can this tube bundle still be designed and made from materials in accordance with ASME standards? Can welded pipes also be used for heat exchange tubes?
Does the national standard not allow the use of welded pipes? Which national standard?
This post was last edited by GSLS on 2015-12-14 at 10:56. This phenomenon is a bit strange. Why must pressure vessels intended for use in China be designed in accordance with ASME standards? The manufacturer already holds the qualifications necessary to produce pressure vessels in China, and yet they are still sold there. Why not use Chinese standards? The relevant regulations set by China’s **Quality Supervision Bureau regarding imported pressure vessels require that they be designed and manufactured in accordance with Chinese standards and that they come with Chinese certification, as well as subject to supervision and inspection ； If containers designed and manufactured in accordance with ASME standards are to enter China, they must undergo inspection by the customs; this is usually carried out by special inspection agencies at the provincial level or above, and the inspection is also conducted in accordance with Chinese standards. Using welded pipes for estimation is not feasible in China; even the special inspection authorities will not approve it.
I personally don’t find this phenomenon strange! For example, in cases where a Sino-foreign joint venture sets up a factory in China and the foreign company provides the entire process package as well as the complete production line, this situation can arise. Therefore, I would like to ask whether there are any viable solutions in such cases!
National standards prohibit the use of welded pipes, mainly because currently there is no reliable quality assurance for such pipes in China, making it difficult to meet the requirements for heat exchange tubes. In the future, as the quality of technological development improves, heat exchange tubes will be included in their scope of use. As for whether domestic welded pipes can be used for replacing heat exchangers in the future, first, it depends on the level of development of industry technology and the allowable standards at that time; second, the ASME standard and imported materials could be considered.
For imported equipment, inspection is carried out in accordance with Annex D of TSG R7004-2013; it is not required that the materials be manufactured and inspected in accordance with domestic standards, only that they comply with the standards of the country from which the equipment is imported, such as the ASME code system. For subsequent maintenance of the equipment, materials that match the equipment’s drawings are generally used – and these are often imported
The tolerance specifications have been made very clear. Regardless of the standards used, this device must be inspected and approved in accordance with Chinese standards when it is manufactured in China ； If the relevant regulations are violated, rejection is possible ； Since it has already been accepted and put into use, in future replacements, other domestic manufacturers can be tasked with producing the tube bundles; even if they are manufactured according to the drawings, all material standards must comply with domestic requirements – there’s no need to worry about this