May I ask about the design pressure of the container?
Thread Content
I would like to ask the teachers: why is there a positive and a negative pressure value for the design pressure of pressure vessels? For example, the design pressure is 1.4/-0.1. Is a strength calculation sheet required for this negative pressure?
The design pressure is 1.4; should it be verified using design pressure - 0.1, right?
Due to the process requirements during operation, both pressures must be taken into account in this design, with special attention paid to the stability check under negative pressure.
During operation, there are two operating conditions for the process; during design, calculations are carried out separately for each of these conditions. Both pressures must be taken into account in the calculations, and calculation reports must be prepared for each of them.
Both operating conditions need to be calculated; generally, design is based on internal pressure while verification is done using external pressure
In addition to what those above have said, it is also necessary to consider whether the stress is alternating; if so, a fatigue analysis is required if more than 1,000 cycles occur during the design life.
It definitely needs to be calculated; this device may experience negative pressure conditions while in use or during replacement； It may operate under negative pressure, but there are high-pressure conditions during steam purging; therefore, the strength at these two design pressures must both be calculated