RE: Conditioning Orifice Plates

From: <Steve>
Date: Thu Jan 27 2005 - 02:41:00 EST

Looks interesting.
Noncompliance with standards will limit application. Greater edge length to flow area ratio suggests performance will drop off more as the sharp corners of the orifices round off. Suspect non - axisymmetric flow will result in poorer regain; higher permanent pressure loss - normally only an issue for the most energy conscious and possibly some of the extreme cryo guys (who probably use venturis anyway).
Am a little suspicious of the 2D upstream requirement regardless of geometry.
Piping drafties will love them.

Cheers

Steve

-----Original Message-----
From: Paul Bowers [mailto:pbowers@pipingdesign.com] Sent: Thursday, January 27, 2005 1:41 PM To: PipingDesign@yahoogroups.com
Subject: [PipingDesign] Conditioning Orifice Plates

Does anyone have experience with these? It seems to be a relatively new technology and I can't see any downside (aside for price maybe, but it's

   really just an orifice plate - how much could it realistically cost?)

http://www.rosemount.com/document/ads/1595_2_01.pdf

Excerpted from the PDF link above:

Table 1 depicts a comparison between conditioning orifice plate technology and standard orifice plate technology, highlighting the deviations from the standards. These deviations allow for a more flexible installation as straight pipe requirements are reduced in some cases by as much as 96%.

[...]

Piping Requirements

Standard orifice plates require significant straight pipe to assure an accurate flow measurement while conditioning plate technology requires only 4 diameters of straight pipe. This equates to significant savings in pipe material costs and allows flexibility in determining flowmeter placement. There are dramatic savings to be obtained when purchasing pipe, in some cases there is up to a 96% reduction in straight pipe requirements.

[...]

Summary

The Conditioning Orifice Plate is a revolutionary innovative technology based on the most common differential primary element in the industry. While not complying with the standards of AGA Report Number 3, ASME MFC 3M or ISO 5167, it is designed based on those standards and provides superior performance in short straight pipe run, tight fit applications with upstream flow disturbances.

• Requires 2 diameters upstream of a flow disturbance and 2 diameters downstream.
  • Decreased straight runs can lower installed cost.
  • Provides flexibility of flowmeter placement and design.
• Compact design reduces installation costs as compared to standard orifice plates.
• Highly accurate and repeatable primary elements.
• Simplified ordering and reduction in inventory, only two betas to choose; one for high flows, one for low flows.
• Suitable for most gas, liquid and steam applications.

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Yahoo! Groups Links Received on Thu Jan 27 02:41:00 2005