Issues regarding the classification of toxic mixtures in pressure pipelines
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Clause 4.4 of GB/T20801.1-2006 \"Code for pressure pipelines – Industrial pipelines\": All versions available online state that when dealing with mixed media with different toxicity or flammability levels, consideration should be given to the medium with the highest level of toxicity or flammability hazard. When the concentration of a hazardous substance is extremely low, a comprehensive consideration of its hazard level and concentration is required, and it is up to the owner or designer to determine the toxicity or flammability category of the mixed substance. In the printed version, as well as in the training materials for pressure pipelines, it is stated that when dealing with mixed media with different levels of toxicity or flammability, a comprehensive consideration of their hazard levels and concentrations is required; it is the owner or designer who decides on the toxicity or flammability category of such mixed media. The difference between the two is quite significant; I’m not sure how to explain it
This post was last edited by kis_ing on 2017-7-12 09:58. The version you found online is likely a draft for feedback or a submission for approval. It must be a text-based PDF. Scanned versions that are identical to the print version can be found online. The standard version should still be the officially published print edition; at the very least, the electronic version should be a scanned copy of the published version – text versions are not reliable
The print version should be checked; it’s possible there was an oversight with the electronic version.
It’s of course correct to go by the paper version, but the standards have been in place for 10 years now – why isn’t there a single electronic version that matches the paper version? I downloaded N electronic versions, and none of them indicated that they were the approved version; none of them had any such indication at all. The reason I raised this issue is to draw everyone’s attention to the fact that some electronic versions that are not marked as approved versions can only be used for reference. When it comes to design work, a paper version is essential; only after verifying that there are no errors in the electronic version can it be used as a basis for design.
This post was last edited by kis_ing on 2017-7-18 09:00. Apart from mandatory standards, general recommended standards do not come in an electronic version issued officially (here, by electronic version is meant a file in.doc(x) format or a PDF file in text form; the most obvious characteristic of such files is that the text can be copied). ) are released; only draft versions or versions submitted for approval appear on the internet, while those officially released come with clear version identifiers. Under normal circumstances, there is not much difference between the draft for approval and the final version; therefore, some people remove the approval markers from these versions and release them as the official version for download. The advantage of this is that the text is clear and can be copied, but it’s easy for discrepancies to arise compared to the final printed version, so caution is needed when using it. The electronic versions of standards that are commonly found online were created after the paper versions were published, with kind people scanning them and uploading them to the internet. This format is the most reliable, with an effectiveness equivalent to that of the paper version; however, issues such as blurred text due to poor scanning quality can occur. Text in this electronic version generally cannot be copied (except in cases where OCR has been used). I’ve attached two electronic versions I found online; one is in text format, and its layout is different from that of the printed version. The content, as the original poster said, is incorrect. The other first part is the scanned version, which is completely faithful to the print version; the content is accurate, so it can be used with confidence.