I have always installed orifice runs in horizontal piping runs with taps below center line by 45 degrees for liquids. Any of you know why an orifice plate would need to be installed in a vertical piping run?

 

Typical mechanical installation considerations might warrant an orifice plate in a vertical run.

- lack of horizontal run
- pump on the ground/floor, pipe goes straight up.
- lack of sufficient horizontal straight run for a meter run, but lots of vertical straight run.
- horizontal run is below grade, not a "nice" environment for a DP xmtr, nor conveniently accessible. Tapping the exit pipe brings the DP above grade.

David

 

For installation convenience possibly?

 

The refinery next to us has 90% of orifice runs in the vertical. The piping is brought to grade from the pipe rack so that control valves can be easily accessed. The orifice run is in the vertical line upstream.

We had an EPC guy fret about "falling flow" once upon a time, insisting that meters had to be in horizontal runs. I can see no sense in this concern personally, but there is another issue: The upstream tap will be a few inches above the downstream tap, creating an offset equal to the differential head of the liquid. They must zero this out because the place has been pounding out gasoline since the late 60's.

As anonymous says, it is mainly for easy access. (both valve and orifice taps, and meter as well if you are "close coupling").

John Rezabek
ISP Lima LLC

 

In two phase-fluid condition, it's necessary to install orifice in a vertical position (up direction flow).