ISO/TR 12767:1998 Measurement of fluid flow by means of pressure-differential devices - Guidelines to the effect of departure from the specifications and operating conditions given in ISO 5167-1
This Technical Report provides guidance to assist in estimating the flowrate when using pressure-differential devices constructed or operated outside the scope of ISO 5167-1.
It should not be inferred that additional tolerances or corrections can necessarily compensate for the effects of deviating from ISO 5167-1. The information is given, in the first place, to indicate the degree of care necessary in the manufacture, installation and maintenance of pressure-differential devices by describing some of the effects of non-conformity to the requirements; and in the second place, to permit those users who may not be able to comply fully with the requirements to assess, however roughly, the magnitude and direction of the resulting error in flowrate.
Each variation dealt with is treated as though it were the only one present. Where more than one is known to exist, there may be unpredictable interactions and care has to be taken when combining the assessment of these errors. If there is a significant number of errors, means of eliminating some of them must be considered. The variations included in this Technical Report are by no means complete and relate largely to examples with orifice plates. There are, no doubt, many similar examples of installations not conforming to ISO 5167-1 for which no comparable data have been published. Such additional information from users, manufacturers and any others may be taken into account in future revisions of this Technical Report.
ISO/TR 12767:1998 history
2023ISO/TR 12767:2023 Measurement of fluid flow by means of pressure differential devices — Guidelines on the effect of departure from the specifications and operating conditions given in ISO 5167
2007ISO/TR 12767:2007 Measurement of fluid flow by means of pressure differential devices - Guidelines on the effect of departure from the specifications and operating conditions given in ISO 5167
1998ISO/TR 12767:1998 Measurement of fluid flow by means of pressure-differential devices - Guidelines to the effect of departure from the specifications and operating conditions given in ISO 5167-1