"4 holes" Conditioning Orifice Plate - who does it work?


Some Rosemount guy was trying to explain to me how great this new 4 hole orifice plate is - saving straight run pipe length before and after the plate.

I find it difficult to visualize how adding 3 more holes will suddenly make all things nice and wonderful.

Just seem too simple or too good to be true...I mean if the flow is still turbulent, it is turbulent right? how does adding 3 holes help?

Any good animation video to illustrate the physics behind it?


  • Hello,

    The reason for the plate saving straight run is that it operates much the same way a flow conditioner does.  It conditions the turbulent flow as it passes through the plate causing a drastic reduction in straight run.  The geometry and location of the holes allow for full flow conditioning across the entire pipe because each hole is sampling a quarter of pipe also causing a mixing effect which normalizes the flow.  Also, the special calibration factor that Rosemount couples with each primary device helps to achieve the best possible accuracy over the entire flow range.  With traditional orifice plates, standards can call out up to 60 diameters total for a meter run.  The conditioning orifice calls out 4 diameters total and improves your accuracy.  With a paddle style and a compact style, it easily fits between flanges and retrofits existing installations that may be performing poorly. 


    The above website should be able to provide you a little bit more detail on the technology as well as specifications, applications, and any other documentation you might be interested in.