Comparing Reg. Orifice Plates to orifice plates w/ flow conditioning
Comparing Reg. Orifice Plates to orifice plates w/ flow conditioning
(OP)
Folks,
I am trying to collect some cost data to compare regular orifice plates to orifice plates with flow conditioning (single plate/multi holes).
I have estimates a reduction in straight pipe lengths of about from 20 diameter (upstream) to 2 d which is giving me considerable saving on large bore lines (24" and 20").
The information that I am missing is:
The additional cost associated with installing conditioning orifices in place of regular orifice.
Can anyone point me to any letterature where I could find this kind of information.
Thank you.
Corradino
I am trying to collect some cost data to compare regular orifice plates to orifice plates with flow conditioning (single plate/multi holes).
I have estimates a reduction in straight pipe lengths of about from 20 diameter (upstream) to 2 d which is giving me considerable saving on large bore lines (24" and 20").
The information that I am missing is:
The additional cost associated with installing conditioning orifices in place of regular orifice.
Can anyone point me to any letterature where I could find this kind of information.
Thank you.
Corradino





RE: Comparing Reg. Orifice Plates to orifice plates w/ flow conditioning
Is your company really allowing someone to design a 24 inch meter station based on hallway rumors? I've rarely heard a scarier concept in gas measurement.
David
RE: Comparing Reg. Orifice Plates to orifice plates w/ flow conditioning
Thank you for the reply.
The orifice plates will used as part of a process control system both in gas lines and liquid lines.
I picked up the 2D from reading vendors websites. Emerson advertises that their meters only require 2D upstream and 2D downstream
thnx
RE: Comparing Reg. Orifice Plates to orifice plates w/ flow conditioning
RE: Comparing Reg. Orifice Plates to orifice plates w/ flow conditioning
Blake Patras
Sales Manager
Miquelon Meter Services
Edmonton, ALberta
RE: Comparing Reg. Orifice Plates to orifice plates w/ flow conditioning
Also, keep in mind that meters claiming to require no straight-run are dependent on beta ratios that allow for maximum flow conditioning. The data I've seen on the 4-hole O-plate is limited, both in pipe size and beta ratio.
We use API 22.2 flow testing protocol for DP devices to show accuracy variations in baseline testing (long straight-run), swirl induced profiles (2 elbows out of plane), and half moon orifice plates (mimicking a half-open gate valve).
Regardless of what meter you choose, I agree with David's statement above about "hallway rumors". Ask for proof - especially in large gas lines - that an accuracy statement is more than just a manufacturer's claim.
Measure it once, you have measurement. Measure it twice, you have an argument. Since you usually don't have the means to "measure it twice", verify the pedigree up front. I understand that it is not practical to independentally test every meter size (thus, the trust that has been placed in standard orifice plates and their reams of empirical data), but I would also ask the manufacturer to back up a claim of .5% accuracy in a 24" gas line with no straight-run and see what they come back with (especially how their K's are derived).
Just my 2 cents.