Classification problem of jacketed vessels
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There is a jacketed vessel available, with an inner cylinder volume of 7.5 m3, an operating pressure of 0.03 MPa, and a design pressure of 0.4 MPa； The jacket volume is approximately 0.08 m3; it is a jacket located at the bottom head, with steam as the working medium. The operating pressure is 0.35 MPa, while the design pressure is 0.53 MPa. Classification method 1: If the working pressure of the inner cylinder is insufficient, no classification is applied ； The jacket is classified as Class I; therefore, this equipment is a Class I vessel ； Classification Method 2: Since the jacket meets the classification criteria, the entire equipment is classified accordingly. The inner cylinder is of Class II, and the jacket is of Class I; therefore, the entire equipment is of Class II. I wonder if anyone has encountered this situation; please give me some advice. Classification errors fall under technical errors, and they are quite troublesome.
Additional note: The inner cylinder contains highly hazardous media
You can refer to the pinned post in this section titled “Judgment of Pressure Vessels” to determine first whether it falls under the scope of pressure vessel regulations. There are 3 main points along with 3 notes. The first point is that the operating pressure must be greater than or equal to 0.1 MPa; obviously, the inner cylinder does not meet this condition. Therefore, this equipment should be classified using Method 1 as suggested by LZ. One more thing: although it falls outside the scope of jurisdiction, this does not mean that all provisions of the regulations are not applicable. The above are just personal opinions, meant to stimulate further discussion
I drew it the same way; the person who checked the drawing said it was incorrect, but several devices are done this way
Speak the facts and present logical arguments; pay attention to the way you do it. Speak kindly if you have something to say. I’m not saying you don’t have a point – you do have one – so don’t act as if you’re being unreasonable. No, let’s all discuss this together, paying attention to the review and approval process for the designs. Take deep breaths
Mm-hmm, thanks, I’ve learned something new:lol
Appendix A of the pressure vessel regulations clearly specifies the classification for multi-chamber vessels, and it is undisputed that the category is Class I. It is worth noting that the inner cylinder contains highly hazardous media, and design and manufacturing inspection requirements shall be established in accordance with GB/T150.
Method 2 is wrong; what kind of logic is this? Nonsense
It can’t be called teaching, but it’s all based on experience – experience gained through pain and hardship :)
Multi-chamber containers are classified according to their individual chambers, with the overall category determined based on the highest standard. The poster’s case involves a highly hazardous medium level in the inner cylinder. It should be noted that in a similar scenario, if the volume of the gas phase space within the inner cylinder is sufficient and the operating pressure is adequate, and the medium is a highly hazardous liquid (with a temperature below its boiling point), then when classifying such a medium, the properties of the liquid must be taken into account, rather than relying solely on the properties of the gas phase space. This reply is unrelated to the case; it’s just a casual addition.