Vapor Pressure Margin
Vapor Pressure Margin
(OP)
What is the minimum Vapor Pressure Safety Margin between the seal chamber pressure and vapor pressure of the process fluid. I am comparing whats best 53B or plan 11 + 52. Rated seal chamber pressure is 17.3 barg and vapor pressure is 16.61 bara. thanks





RE: Vapor Pressure Margin
RE: Vapor Pressure Margin
Thanks for these data, i will look again on the API 682 as this is the fact i'm looking now for almost 3 days and yet not found. Is it also a rule of thumb that the seal chamber pressure should be higher than 1 bar to the fluid vapor pressure?
RE: Vapor Pressure Margin
It is at the bottom of Page 25 of the 3rd Edition.
The rules of thumb I have used in the past were 25 psig higher for S.G. > 0.5 and 50 psig higher for S.G. < 0.5. I am not sure now whether they came from other standards, an earlier version of 682 or were just company standards.
For me, therefore, 1 barg margin would not be enough.
RE: Vapor Pressure Margin
Thanks for the infos. I have now found the corresponding page....