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Where Can I Purchase an NIST Calibrated Orifice ?

Where Can I Purchase an NIST Calibrated Orifice ?

Where Can I Purchase an NIST Calibrated Orifice ?

(OP)
I am trying to find out where I can purchase an NIST calibrated orifice.  

RE: Where Can I Purchase an NIST Calibrated Orifice ?


Don't believe that NIST calibration of an orifice plate is available.

What you typically specify is a hydraulic test in a certified flow lab. Typically a water test is used to confirm the discahrge coefficient over a given reynolds number range.

Some of the critical flow nozzles can be traceably calibrated, but these are used to set flows for flow testing not measurement.

RE: Where Can I Purchase an NIST Calibrated Orifice ?

Testing a single orifice in an NIST certified hydraulic lab is a waste of time and money in most cases.  The performance of the orifice plate will be determined based upon the lab piping into which it is installed and  tested.  When the orifice is subsequently installed in the field, it is rare that the piping would match that of the testing facility.   

The orifice plate represents one component of the primary flow element assembly.  The other components are the meter tappings (ie. flange, corner, radius, pipe) and the required up and downstream controlled ID piping.

The complete assembly should be supplied from a reputable meter manufacturer and forwarded to the testing facility for performance evaluation.  

Hope this helps.

bk

RE: Where Can I Purchase an NIST Calibrated Orifice ?



at the risk of hihacking the original post, flow testing is used to define the meter coefficient. This is always performed in an assembly (meter and meter tube) purchase together and frequently used in custody transfer applications.

it is hardly a waste of time and eliminates an often contentious issue when questions of the metering accuracy are being debated.

A true flow calibration is rarely performed as it would require using the process fluid at the actual pressure and temperature, etc.


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