Discussion on sanitary-grade pressure-resistant quick-opening manholes
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This post was last edited by KmFstyle on 2017-11-20 at 14:52. For manholes on pressure vessels, it is sufficient that they meet the requirements regarding pressure resistance and corrosion resistance. Recently, our factory undertook a series of tasks related to the manufacturing of pharmaceutical containers. After the design drawings were prepared, the client requested that the pipe openings, including the manholes, be converted to the quick-opening designs commonly used in pharmaceutical containers. These manholes needed to meet hygiene standards as well as GMP requirements. Since quick-opening devices such as clamps or hook bolts are rarely used on pressure vessels, the standard manholes specified in HG/T 21527 also fail to meet the requirements for hygiene – namely ease of cleaning, smooth surfaces, and being lightweight and thin. Therefore, I went to pharmaceutical companies and saw that many tanks used the type of hygiene-grade manhole shown in the following links: https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1511170768955&di=0435f37a3f900ebe72007e0bebaade99&imgtype=0&src=http%3A%2F%2Fimg010.hc360.cn%2Fhb%2FMTQ3MTQzNDA1Mzg2My05MTA1OTAwMzc%3D.jpg, https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1511170797745&di=28daa5ac19f8d538611743318d022069&imgtype=0&src=http%3A%2F%2Fwww.jdzj.com%2FUserDocument%2Fwzwanmu%2FPicture%2F20113910248.jpg. After checking online, many manufacturers refer to this type of manhole as model YAD or YAA. However, these manufacturers claim that such structures can withstand a pressure of around 5 KG, but it’s not clear what standards are used for their manufacture, and no relevant information can be found. Since these manholes will be used in the inner cylinder of jacketed vessels (where the internal pressure is less than 0.1 MPa and the water pressure is 0.125 MPa), what steps need to be taken to verify whether these structures can meet the pressure requirements? How is it used on pressure vessels? I would like to ask the experts here for their advice; I hope they can come up with some solutions. Thank you all in advance!
Since the wall thickness of these manholes is very thin, there is concern regarding their reliability, and no corresponding manufacturing standards can be found. This leads to confusion as to how such manholes can be used in equipment in a legal and compliant manner. Such manholes are common in pharmaceutical equipment, and manufacturers produce them as standard components, but they fail to specify which standards are followed in their production
Some manufacturers have such books; those in the industry are aware of this
At present, the standard used in China is basically the enterprise standard QBJ-B01-2004 \"Hygienic quick-opening manholes and handholes\", formulated by Wenzhou Industrial Design Institute (hereinafter referred to as Wenzhou Standard). The latest version should be 2013
QBJ-B01.01~01.07-2013 Quick-opening manholes; feel free to contact me if you need them
A new thread has just been created to make it easier for those who need it to find it; the original poster can go and download it at https://bbs.hcbbs.com/thread-1869141-1-1.html