Whether a heat exchanger falls under the definition of a pressure vessel
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Definition of pressure vessels: Pressure vessels refer to enclosed devices used for holding gases or liquids and subjected to certain pressures. They include fixed and mobile vessels whose maximum operating pressure is 0.1 MPa (gauge pressure) or higher for gases and liquefied gases, and whose maximum operating temperature is equal to or higher than their standard boiling point; such vessels also have a volume of 30 L or more and an inner diameter of 150 mm or more (for non-circular cross-sections, this refers to the largest geometric dimension of the cross-sectional boundary). There is a pressure vessel available now: the inner diameter of the tube side is 19 mm, the volume is 0.2 m², the fluid used is liquid nitrogen, and the pressure is 17 MPa. The inner diameter of the shell side is 1142 mm, the volume is 2.5 m², the fluid used is hot water, and the pressure is at atmospheric level. So, does this heat exchanger qualify as a pressure vessel? Do we need to consider the tube side and the shell side separately?
Vessels with atmospheric pressure in the shell side and an inner diameter of the tube side < 150 mm, classified as outside category and not subject to inspection
Heat exchangers are multi-chamber containers, and the pressure chambers should be classified separately, with the highest category being used as the classification for regulatory purposes. For details, see TSG21-2016ZHONG a1.3.2. What you’re referring to is mainly whether it is subject to regulation, that is, whether it falls under a certain classification. To be eligible for classification under TSG21, the inner diameter of the tube side and the operating pressure of the shell side must meet the specified requirements; since these criteria are not met in your case, the entire unit does not fall under any classification and is therefore not subject to regulation.
Is it a fixed-tube-sheet heat exchanger? The inner diameter of the tube side you mentioned should refer to the inner diameter of the heat exchange tubes. What is the diameter of the tube box, and what is the operating temperature?
The shell side is definitely exceptional; as for the tube side, it’s impossible to have only heat exchange tubes without a tube sheet. If the diameter of the tube box is greater than 150, it needs to be classified, and in that case it must be treated as a pressure vessel
You can search on Baidu for “SG-21—2016《Safety Technical Inspection Regulations for Fixed Pressure Vessels》Course Materials-2017ppt”... and you will find the accurate answer
All the senators are great; thumbs up!
The parameters provided by LZ are incomplete, so it’s impossible to determine the classification
This post was last edited by xlxuiin on 2018-11-9 at 11:29. It should be a liquid nitrogen heater. The inner diameter of the tube is 19 (this should refer to the inner diameter of the heat exchange tubes, with the material being stainless steel or copper); it does not represent the inner diameter of the tube bundle. (Since the inner diameter of the shell side is 1142, the overall outer diameter of the tube bundle should correspond to that value.) In other words, the diameter of the tube bundle is around 1 meter, with a volume of 0.2 cubic meters. So, a supervision process is definitely a pressure vessel (subject to regulatory oversight) ； There is no classification for the shell side, and no supervision is required.