The problem of classifying containers
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A vertical jacketed container. The inner cylinder is at atmospheric pressure, and the medium inside it is a highly hazardous, flammable, and explosive substance. The jacket contains water and water vapor generated by the vaporization of the water in the jacket due to the medium inside the inner cylinder; the pressure is 0.9 Mpa. Classifying it as Category 1 – is that correct?
Yes. This classification method is mentioned in pressure vessel training materials.
1. A pressure vessel falls under Category 3 in any of the following situations: (1) High-pressure vessel； (2) Medium-pressure vessels (only for media with extremely high and high toxicity) ； (3) Medium-pressure storage vessels (only for flammable or moderately hazardous media, with a PV product greater than 10 Mpa·m3); (4) Medium-pressure reaction vessels (only for flammable or moderately hazardous media, with a PV product greater than or equal to 0). 5 Mpa·m3); (5) Low-pressure vessels (media with extremely high or high toxicity, and a PV product of 0.2 Mpa·m3 or greater) ； (6) High-pressure and medium-pressure shell-and-tube waste heat boilers ； (Note 4) (7) Medium-pressure glass-lined pressure vessels ； (8) Pressure vessels manufactured from materials with a high strength level (meaning that the minimum specified value for tensile strength in the relevant standards is 540 Mpa or higher) ； (9) Mobile pressure vessels, including railway tank cars (for liquefied gases and cryogenic liquids), tank trucks, and tank containers (for liquefied gases and cryogenic liquids), etc ； (10) Spherical storage tanks (volume greater than or equal to 50 m3) ； (11) Storage vessels for cryogenic liquids (volume greater than 5 m3). 2. A pressure vessel falls under Category II in any of the following circumstances (except as specified in Paragraph 1 of this article): (1) Medium-pressure vessels ； (2) Low-pressure vessels (media with extreme and high toxicity levels) ； (3) Low-pressure reaction vessels and low-pressure storage vessels (only for flammable media or media with moderate toxicity) ； (4) Low-pressure shell-and-tube waste heat boiler ； (5) Low-pressure glass-lined pressure (6) Pressure vessels. 3. Low-pressure vessels are classified as Class 1 pressure vessels (except as provided in Paragraphs 1 and 2 of this article).
Please refer to Note 2 on P9 of the Specifications!
Class 1 pressure vessels are correctly classified.
It’s not necessarily one category; it depends on the size of the inner cylinder. It could be category three, or at least category two. Otherwise, it doesn’t fall under the scope of the pressure vessel regulations. Please read Note 1 in the Pressure Vessel Regulations carefully. This post was last edited by gzk1986 on 2009-2-10 at 17:20.]
Please, the guy on the 9th floor, explain clearly why it’s necessary to check the volume of the inner cylinder.
It indeed should be classified into one category; that’s correct
The inner cylinder is at atmospheric pressure and does not require classification; it holds highly hazardous media, and strict requirements can be applied in terms of manufacturing processes and non-destructive testing； The jacket water vapor is at a temperature above the standard boiling point, with a pressure of 0.9 MPa; it should be classified as a Class 1 pressure vessel
Multi-chamber containers should be classified separately: the interior of the cylinder is at normal pressure and does not require special classification, while the jacket constitutes a separate category; the highest classification level should be applied, That is, that of one category
It must be a type of container that meets the requirements specified in the container regulations