Problem:

Why does the MAP calculation change with different Hydrotest vessel orientations in AutoPIPE Vessel?

Example: 

When selectin Vertical MAP = 1.48, when selecting Horizontal, MAP = 1.45, why?

Solution:

MAP calculated is reduced by the hydrostatic pressure considered (bottom or code pressure) to get the final MAP.

MAP final = MAP calculated - Delta Pt

Why? To not overestimate the test pressure or, in other words, to not have a test pressure at the bottom higher than the Design Pressure. The MAP is used to calculate the test pressure. In Hydrotest, the hydraulic head is added afterwards-.

So the difference between one and another is just Delta Pt:

That’s why we have 1.45 MPa in one case and 1.48 Mpa in the other.

This part is found at the bottom of the hydrostatic TestPressure report (the same the user took the screenshots from)