Query Regarding Flow Straightner/Profiler plate

Dear Sir,
We are currently planning to use 2” Senior orifice fittings for 2” sch 160 pipeline. However due to delivery issue, we have planned to use sch 80 senior orifice fittings. As the fittings are welded connection, we have no issue in welding this senior orifice fittings.
My main concern is on the installation to use profiler plate (flow straightner plate). As we are buying Sch 80 Senior Orifice fittings, Emerson supplied us sch 80 profiler plate similar to senior orifice fittings. However our piping is of sch160 rated. As both profiler plate (sch 80) and piping diameter (sch 160) is different the fitting will not fit due to the different geometry. Hence we have requested for a new sch 160 profiler plate which can fit to sch 160 piping.
Can you please confirm any drawbacks of using sch 160 profiler plate with the sch 80 Senior Orifice fitting. Any impact on accuracy and pressure drop, etc. issue, please highlight.
Thanks & Regards
Suhas Karekar
Process Design Engineer

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3 Replies

  • Dear Suhas,

    Thank you for your question. If I understand correctly you have a 2" Sch80 Senior orifice fitting and a Daniel Profiler and you are intending to use them in Sch160 connecting piping.

    To achieve the best measurement accuracy with an orifice measurement, we recommend meeting the requirements of the international standards concerning orifice plate usage. For your question, this means that all components of the measurement should be of matching pipe schedule. Both the Senior and the Profiler should match the pipe schedule of the connecting piping. If you have unmatched pipe schedules, you will have a measurement error. However, it is difficult to determine the amount of inaccuracy and whether it would read too high or too low.

    If you need more details, I would be glad to assist further.

    Thank you,
    Steve Ifft
  • Thanks Steve,
    Appreciated your well written response.
    Can you provide your input on below?

    1.     Whether it is necessary to use flow conditioner plate?

    2.     There are multiple design of flow conditioner plate (plate type, tube type etc), any guideline which is to be used for gas service.

    3.     Any recommended guideline, where we can maintain minimum upstream/downstream distance for the flow conditioner plate?

    Thanks & Regards
    Suhas Karekar
    Process Design Engineer
  • In reply to suhas.karekar:

    Hi Suhas,

    1. Flow conditioning plates are commonly used in orifice meter tubes but are not always necessary. These plates condition the flow and remove disturbances caused by upstream piping elements such as elbows and valves. Having a flow conditioning plate allows users to shorten the installation length of the overall meter tube significantly and still meet the uncertainties specified in the standards. Without a flow conditioning plate the upstream straight piping requirements are much longer, per the international standards.

    2. Daniel typically recommends the plate style of flow conditioner in gas applications. There are two major types of flow disturbances that can affect flow meter accuracy, swirl and asymmetry. The plate style flow conditioner will remove both types of flow disturbances. A tube style flow conditioner (or tube bundle) will only effectively remove swirl but not the asymmetry. While the plate style will add more pressure loss to the system, they are more effective in removing disturbances that cause inaccuracies in flow measurement.

    3. Each manufacturer of flow conditioning plate has their own requirements for upstream and downstream installation lengths. You can find information on the Daniel Profiler here: www.emerson.com/.../43724.pdf

    Thanks for your questions and interest in our products.