Static or Total Pressures

[Flarenuf]

I know API520/521 basis its design on static pressures. But what does a standard type pressure gauge in a line show? Static pressure or total pressure. Do you have to use a more complex means to measure total P.

 

[patrickraj]

Dear BIFFOFO

PI's indicate STATIC PRESSURE only.
To know the true pressure(at the point of PI tapping), you have to add pressure gauge elevation and velocity head.