Regarding the classification of containers

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This post was last edited by hebeizhengyuan on 2017-10-31 17:01. We have recently designed a pressure vessel; its structure is shown in the attached diagram. The tube side contains high-pressure gas with a design pressure of 31.4 MPa; the maximum inner diameter of the header tubes is 140 mm, while the shell side is filled with steam. In accordance with the requirements of Code 1.3, the PV value for the shell side, as determined from the tables, classifies the vessel as a Class I vessel. The tube side falls outside the scope of Code 1.3 because the maximum diameter of the header tubes is less than 150 mm (the tubes are of DN25 size); therefore it is classified as not falling into any specific category. As a result, the entire equipment is classified as a Class I vessel. During the manufacturing process, the inspectors from the local inspection department said that our classification was incorrect; it should be classified as a Class III container. Their reasoning was as follows: First, this equipment falls under the regulations regarding classification. Since it is governed by those regulations, the tubes and shell sides are classified separately based on various PV values, and the overall classification of the container is determined by the higher category among those of the tubes and shell sides. This equipment has a tube side volume of 400 liters and a pressure of 31.4 MPa; it uses the first type of medium, and the entire equipment should be classified as a Class III vessel. Due to disagreements, the inspection personnel refused to inspect this equipment. Colleagues, are their opinions correct? How do you classify such containers?