Why is the maximum allowable operating pressure of a container greater than the design pressure?
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Why is the maximum allowable operating pressure of a container greater than the design pressure?
If the definition of the maximum allowable operating pressure is clarified, there will be no doubts.
Working pressure, maximum working pressure, design pressure, maximum allowable working pressure – do not confuse the two with the four
This issue seems to have been discussed many times.
It is necessary to understand when the maximum allowable operating pressure is required.
The design pressure corresponds to the calculated thickness, while the maximum allowable operating pressure corresponds to the effective thickness; the effective thickness is the calculated thickness plus an integer value.
This issue is relatively easy for pressure vessel designers to understand. It is relatively difficult for those who are not pressure vessel designers to figure this out.
The maximum allowable operating pressure of a container is sometimes equal to the design pressure.
The maximum allowable working pressure of a vessel refers to the maximum gauge pressure that the top of the vessel is permitted to withstand at the design temperature. This pressure is calculated based on the effective thickness of the container shell, and the minimum value is taken. When a container equipped with a relief device uses the maximum allowable operating pressure as its design burst pressure, the hydrostatic and airtightness test pressures for the container shall be increased accordingly in accordance with relevant regulations, and this shall be indicated on the drawings and nameplate.
The design pressure is determined based on the maximum operating pressure, which in turn is calculated from the wall thickness of the container. For example, if the design pressure is 1.0 MPa, the calculated wall thickness is 4.5 mm; after adding safety margins, the actual material thickness used may be 5 or 6 mm. The pressure deduced from the thickness of the material used is the maximum allowable operating pressure, which is obviously generally higher.