[Weekly Topic] Are the operating and design pressures of pressure vessels absolute pressures or gauge pressures? (2011.08.15-08.21)
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This post was last edited by wangtianyi*ao on 2011-8-15 at 13:12. While designing a vapor-liquid separator today, I suddenly realized that it is necessary to consider the operating pressure and design pressure at different temperatures. Therefore, the topic for this week is: Are the operating pressure and design pressure of pressure vessels absolute pressures or gauge pressures? (Note: Absolute pressure = Gauge pressure + 1 standard atmosphere)
Absolute pressure is used in process calculations, while gauge pressure is used in mechanical calculations of equipment. Whether it is process design or mechanical design, it is necessary to specify which type of pressure is being used; generally, absolute pressure is indicated by a (A), and gauge pressure by g (G). In the case of mechanical design, any value that is not specified refers to gauge pressure.
The operating pressure and design pressure of pressure vessels are gauge pressures; according to 3.4.1 of GB150, unless otherwise specified, all pressures refer to gauge pressures.
Agree with the second floor: Generally, absolute pressure is indicated as A, while gauge pressure is indicated as G
It is generally gauge pressure... specified in both GB150 and the pressure vessel regulations.
Reply to 2# ljc: Do the lowercase letters a and g represent values?
This post was last edited and replied to by wangtianyi*ao on 2011-8-15 at 17:32. Reply 7# luoye888: I disagree with your view; work pressure and design pressure should be gauge pressure. The reason I raised this topic is that for a vapor-liquid separator operating at a working temperature of 170 degrees Celsius, it is necessary to first determine the absolute pressure using a table, and then subtract one standard atmosphere to obtain the gauge pressure. (The calculation method for design pressure is the same). When I built similar vapor-liquid separators in the past, I made a mistake by mistaking absolute pressure for gauge pressure. But this error will not cause issues with the equipment’s strength calculations; it’s not a big problem. If I encounter such a problem again in the future, I won’t make the same mistake.
The lowercase letters a and g represent absolute pressure and gauge pressure
It is usually gauge pressure. . . . . . .