Classification of R22 storage tanks
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What category of vessel is the 50m3 Freon R22 storage tank classified as?
Classified as a liquefied gas, with a design temperature of 50°C and a design pressure of 2.2 MPa; it should be classified as Category III equipment according to TSG21； But some are classified as Category II – based on what standard?
Under current regulations, liquefied gases are classified as Group 1 media and should be considered Class III pressure vessels.
Some are designated as Category II, probably from very old drawings.
The refrigerant, being a liquefied gas, is classified as a Class III pressure vessel based on its design pressure and volume.
For drawings classified as Category 2, it is estimated that the specifications from version 99 will still be applied; at that time, media were not grouped, and classification was based solely on extreme and high hazards, as well as moderate hazards and flammability, in combination with pressure levels.
Thank you all for your participation! After consulting several design institutes and special inspection agencies, it was determined that given the low hazard level of the R22 medium, it can be classified as a medium in Group 2. Following this logic, the 50m3 R22 storage tank can be classified as a Class II vessel.
The opinions of the design institute and the special inspection institute are inappropriate; Annex A of TSG21-2016 explicitly classifies liquefied gases as belonging to Group 1 of media, and with PV=110 and P=2.2, they can only be classified as Category III.