Operating pressures of several media during storage at room temperature

Maybe the testing conditions are different.

So how should the values be chosen during design?

I think choosing a higher value is safer.

This post was last edited by Forgetting = Forgetting on 2017-10-23 23:55. “”Informational“” – this is the key point

The key is that the difference is significant, especially for propylene

Note that the units in the table are MPa(A), which refer to absolute pressure; the unit values shown in the gauge specifications all refer to gauge pressure. However, there are still differences between the two tables, and if the original poster checks the relevant medium manuals, they will find that these values are incorrect. Using interpolation: the pressure of propane at 50°C should be 1.752 MPa (absolute pressure), while that of propylene is 2.103 (absolute pressure). The reason is that saturated vapor pressures like this are obtained through experiments, and then curves are derived from them. Those who consult the tables determine the values based on the curves. So there will be errors. In fact, this impact is not significant, as the standards specify that the saturated vapor pressure at 50°C should be used as the operating pressure; therefore, there is still a margin when determining the design pressure.

Below is a screenshot from a material manual showing that the vapor pressures of propylene, propane, and isobutane at 50°C are 2.041 MPa, 1.7001 MPa, and 0.6775 MPa respectively.

The units in the Pressure Vessel Media Manual are also absolute pressure; therefore, if one wants to delve into this further, one can only ask the compilers of the major regulations.

Then, according to your opinion, what values should be assigned to the operating pressure and design pressure for the storage tanks used to store these three media at room temperature?

Asking the editor of Da Rong Gui usually gets no answer...