Classification criteria for heat exchangers
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In the classification of heat exchangers, if the medium in the tube side is highly hazardous, is the volume calculated as the square of the inner diameter of the heat exchange tubes multiplied by the length of those tubes and then multiplied by the number of tubes? If this value reaches 0.025 cubic units, and the maximum operating pressure is greater than 0.1 MPa, should this be used as the basis for classification? If the medium in the shell side is highly hazardous, is the volume calculated by subtracting the volume of the heat exchange tubes from the inner diameter of the shell? If this value reaches 0.025 cubic units, and the maximum operating pressure is greater than or equal to 0.1 MPa, should this be used as the basis for classification? Conversely, if these three criteria specified in the regulatory standards cannot all be met, does it mean that the device is not subject to those regulations? Please advise! Thank you
Article 2 of the Regulations: The scope of these regulations is as follows: 1 These regulations apply to pressure vessels that meet all of the following conditions: (1) The maximum operating pressure (Pw) is greater than or equal to 0.1 MPa (excluding hydrostatic pressure); (2) The inner diameter (for non-circular cross-sections, this refers to the largest dimension) is greater than or equal to 0.15 m, and the volume (V) (Note 2) is greater than or equal to 0.025 m3; (3) The medium contained within is a gas, a liquefied gas, or a liquid whose maximum operating temperature is greater than or equal to its standard boiling point. Note 2: P represents the design pressure, Pw represents the maximum operating pressure, and V represents the volume. Volume refers to the geometric volume of a pressure vessel, that is, the volume calculated from the dimensions specified in the design drawings (without considering manufacturing tolerances) and rounded off, without deducting the volume of the internal components. Multi-chamber pressure vessels (such as the tube side and shell side of heat exchangers, the drum and heat exchange chamber of waste heat boilers, jacketed vessels, etc.) are classified according to the chamber with the highest design pressure, and are managed and used under that category. However, when categorizing by each pressure chamber, the design pressure shall be taken as this pressure, and the volume shall be taken as the geometric volume of that pressure chamber.
The volume of the tube bank is calculated as the total volume of the heat exchange tubes plus the volume of the tube box； The volume of the shell side is calculated without deducting the volume of the heat exchange tubes.