Airtightness test
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Currently, a floating-head heat exchanger is being designed with a tube side design pressure of 1.9 MPa, using carbon monoxide as the fluid, a volume of 2 m³, and a diameter of DN700. According to HG/T20660-2017, CO is classified as a highly hazardous substance. In line with the relevant regulations and GB150 requirements, after passing the pressure test, pressure vessels whose medium is extremely or highly hazardous, or those for which even trace leaks are not permitted due to design considerations, must undergo a leakage test. There’s some confusion now regarding whether to conduct a airtightness test; waiting for answers from colleagues online.
This post was last edited by fzujunru on 2020-11-8 at 20:16. Carbon monoxide is classified as moderately hazardous in HG20660-2000, but as highly hazardous in the 2017 version. Is that what’s bothering you? From the perspective of regulations and standards, according to the 2000 version, the authorities have also responded to this question on the message board. The most important thing is to discuss it with the local special inspection agency and consider their opinions
Yes, the manufacturing cost has increased a lot according to 2017 standards. Thank you for your answer.
1. The General Administration has stated that it is indeed required to determine the toxicity of the medium in accordance with HG20660-2000; however, some large design institutes are more cautious and prefer to use the new standards from 2017. 2. As a designer, if you determine the toxicity of the medium based on HG20660-2000, you will constantly have to explain this to various parties, such as clients, inspection agencies, and experts during re-certification processes. 3. If there is a leak during the operation of this equipment, it will be difficult for the designer to avoid taking responsibility. Therefore, my personal suggestion is that the toxicity of the medium can be determined according to HG20660-2000, but it would be better to include pressure testing requirements in the technical specifications, so as to avoid unnecessary problems in the future
Thank you for your answer. From the perspective of individual responsibility, it is better to conduct a leak test; if a leak test is carried out, it is still preferable to determine the toxicity of the medium in accordance with the 2017 standards.
Personally, I think that according to HG/T20660-2000, a response from the competent authority can be used as a shield, and this provides a basis for such action. However, the designer has the right to raise the technical requirements; if they feel it is necessary to add air-tightness tests, then this can also be done in accordance with the new HG20660-2017 standards regarding toxicity
Thank you very much for your answer! Thank you!
Do dielectric properties relate not only to airtightness testing but also to other design and manufacturing requirements?
How are the medium properties specified on the drawings?