Pressure vessels with working pressure at atmospheric pressure
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Case: A container with normal operating pressure, a volume greater than 0.03 cubic meters, containing the highly hazardous substance HF; it is classified as outside this category in the drawings. In my opinion, with a normal pressure of 0.1 MPa, it should fall into the above category of containers. I hope a friend by the sea can clarify this for me.
This post was last edited by wanlirn on 2022-8-8 at 15:00. Who told you that the normal pressure is 0.1 MPa? Media that are highly hazardous and explosive in normal-pressure containers should be designed and manufactured in accordance with GB150, but classification is not taken into account
What is the pressure at atmospheric pressure? In this case, the operating pressure is at atmospheric pressure, while the design pressure is 0.1 MPa
The working pressure specified in the catalog of special equipment and in the technical specifications refers to gauge pressure, and it is indicated in parentheses. The concept of normal pressure generally refers to 0.02 MPa < design pressure < 0.10 MPa. There is no concept of normal pressure in laws and regulations; it is merely an industry term that is occasionally referenced in such laws and regulations.
Thank you for clarifying. I have another question: can Type A flat welding flanges be used as container flanges for high-hazard media? This is not specified in NB/T47020
This is your personal perception; according to the standards, it falls outside the category
The working pressure at normal conditions does not comply with TSG, so it is not classified
The operating pressure is at atmospheric pressure, while the design pressure is greater than 0.1 MPa; it is designed, manufactured, and inspected in accordance with GB150. However, it falls outside the pressure range covered by relevant pressure equipment regulations, so it is not considered a pressure equipment device, and GB150 applies to it
(1) The design of pipe flanges, gaskets, and fasteners for steel pressure vessels shall comply with the provisions of the HG/T 20592–HG/T20635—2009 series of standards titled \"Steel Pipe Flanges, Gaskets, and Fasteners\"； (2) For pressure vessels containing liquefied petroleum gas, media with extremely high or high toxicity, as well as highly permeable media with moderate toxicity, the pipe flanges shall comply with the provisions of the HG/T 20592–HG/T 20635 series of standards, and should utilize necked butt-weld flanges, metal wound gaskets with reinforcement rings, and specially graded high-strength studs ； Where such pipe flange sealing combinations cannot be used, the designer shall determine the flange connection design based on the properties of the medium, pressure, and temperature.
Pipe flanges are manufactured in accordance with relevant standards. For container flanges, can standard flanges specified in NB/T47021 be used for high-risk media? Or can flanges conforming to NB/T47021 be used as long as a sealing structure combining gasketing and specially graded high-strength studs is adopted?