API MPMS 14.12

Abstract

This Standard addresses the following: a) provides generic information on full-bore vortex shedding flowmeters, including glossary, and sets of engineering equations useful in specifying performance; b) describes vortex shedding flowmeters in which alternating vortices are shed from one or more bluff bodies installed in a closed conduit; c) describes how the vortex shedding frequency is used to determine the velocity to infer the volume, mass, and/or energy flow rate and the total gas flow through the meter over a specific time interval; d) applies only to single phase gas flows in closed conduit that are steady or vary slowly in time. For fiscal measurement, the output of the flow rate shall be within the acceptable limits of steady state flow rate; e) describes the physical components of vortex shedding flowmeters and identifies need for inspection, certification, and material traceability; f) addresses the effect of gas properties, installation, and process conditions that may affect the measurement uncertainty and describes guidelines for reducing or eliminating their influences; g) defines the method for calculating uncertainty of the flow rate measurement; h) defines the meter output requirements and necessary information pertaining to the meter output for the purpose of fiscal measurement of gas; and i) provides calibration and/or performance verification guidance for the field application. COMPLIANCE The manufacturer is responsible for complying with all of the provisions of this specification. The purchaser may make any investigation necessary to satisfy himself of compliance by the manufacturer, and he may reject any material that does not comply with this specification. It is urged that the purchaser avail himself of this right and furnish his own inspection independently of any supervisory inspection furnished by the manufacturer, and that the purchaser\'s inspector follow closely all of the details of field construction and testing herein specified which affect the integrity and safety of the completed structure.