Open a post to explain the definitions of various pressures in pressure vessels to friends who don’t like to read.
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This post was finally edited by Zhang Junli on 2022-3-14 14:21 to explain the definitions of various pressures in pressure vessels to friends who don’t like to read. Don’t read old posts again. 1. Maximum allowable working pressure: The maximum pressure allowed at the top of the container at the corresponding specified temperature. The pressure is calculated based on the effective thickness of each pressure component of the vessel, taking into account all loads borne by the pressure component, and takes the minimum value. 2. Design pressure: Set the maximum pressure at the top of the vessel, together with the corresponding design temperature, as the basic design load condition of the vessel, and its value shall not be lower than the working pressure. 3. Work pressure: It refers to the highest pressure (gauge pressure) that may be reached at the top of the pressure vessel under normal operating conditions. [Commonly known as maximum working pressure, operating pressure, etc.] 4. 5. Safety valve setting pressure: The inlet pressure at which the safety valve disc begins to lift under operating conditions. 6. Burst pressure: Rupture disc bursting pressure. 7. Pressure resistance test pressure: TSG 21-2016 3.2.12.1 According to calculations, the rough hydraulic pressure is 1.25 times the value (design pressure or maximum allowable working pressure or allowable (monitoring) use pressure), and the air pressure is 1.1 times the value. 8. Air tightness test pressure: Take the design pressure or allowable (monitoring) operating pressure. 9. Allow (monitor) usage pressure: Periodically inspect and approve the maximum pressure. 10. Check pressure: The pressure for strength verification is generally the allowable (monitored) use pressure. The relationship between pressures: Maximum allowable working pressure ≥ design pressure ≥ safety valve setting pressure (usually 1.05-1.1 times the working pressure) / burst pressure ≥ working pressure ； Pressure test pressure > Air tightness test pressure ≥ working pressure ； Calibration pressure is generally between working pressure and design pressure ； Calculated pressure ≥ design pressure. Attached is the relationship between thicknesses: GB 150-2011 B4.7 As for other unmentioned errors and errors, please reply and correct them!
Hello, Mr. Zhang, I have used the drawings you designed. I am glad to see you!
The above are the main pressures mentioned, such as liquid column static pressure, safety valve, sealing test pressure, air tightness test pressure, discharge pressure, opening pressure and the above mentioned pressures are not the same.
The pressures do not completely follow the above relationship. Prerequisites are required. Under different preconditions, some magnitudes will be reversed. This is generally the case. At the same time, it is also equivalent to considering the general limit situation.
Shouldn't the design pressure be the highest? The design pressure should be the pressure that the equipment or pipeline endures during normal operation multiplied by a safety factor to get the design pressure, right? Will operating above the design pressure cause damage to equipment or pipelines?
Of course, the ratio between design pressure and working pressure is high, and no one allows you to operate beyond the design pressure. But the equipment is capable of withstanding pressure exceeding the design.
Allowing exceeding the design pressure does not mean that it is allowed to operate beyond the design pressure, so I personally feel that the maximum working pressure ≥ design pressure is not appropriate. Represents only personal views.
The operating pressure cannot exceed the maximum working pressure. The maximum allowable working pressure is not the maximum working pressure you mentioned. The design pressure is a set value and is designed based on the design pressure, but it does not mean that only the design pressure can be used. It is just that you did not understand the definition. You can read it again in detail. Indeed, the noun is written with the same meaning as in normal use.
As shown in the picture, I would like to ask what the working pressure and working temperature in the container design data sheet have in practice. For example, the design pressure is 0.35MPa and the working pressure is 0.101MPa. Why not write ≤0.35MPa?； The design temperature is 160/-19.9 and the operating temperature is 18.7/6.3. Why not write -19.9-160℃. In addition, when the pressure vessel is inspected regularly, the vessel is in good condition. Should the allowed working pressure be written as ≤0.35MPa or 0.101MPa? ； Is it allowed to use temperature to write -19.9-160℃, or 6.3-18.7℃? Thanks.