AGA Report No.3 recommends fabrication of the 1998 Uniform Concentric

19-tube bundle flow straightener. No flow conditioner can eliminate all possible

profile effects unless properly installed and used. Care should be taken to minimize

flow disturbances and swirl-generating configurations in the metering system,

particularly upstream of the orifice. Thus, when properly located, in well designed

installations, the 1998 Uniform Concentric 19-Tube Bundle Flow Straightener can

eliminate bias in orifice measurement. For further information on proper installation

of this flow straightener.