API MPMS 5.8 2011 pdf download.
2 Normative References The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. API MPMS Chapter 4.5, Master-Meter Provers API MPMS Chapter 4.8, Operation of Proving Systems API MPMS Chapter 6.1, Lease Automatic Custody Transfer (LACT) Systems API MPMS Chapter 6.2, Loading Rack Metering Systems API MPMS Chapter 6.4, Metering Systems for Aviation Fueling Facilities API MPMS Chapter 6.5, Metering Systems for Loading and Unloading Marine Bulk Carriers API MPMS Chapter 6.6, Pipeline Metering Systems API MPMS Chapter 6.7, Metering Viscous Hydrocarbons API MPMS Chapter 13.1-1985, Statistical Concepts and Procedures in Measurement API MPMS Chapter 21.2, Electronic Liquid Volume Measurement Using Positive Displacement and Turbine Meters 3 Terms and Definitions For the purposes of this document, the following definitions apply. 3.1 acoustic path The path that the acoustic signals follow as they propagate through the measurement section between the acoustic transducer elements.
3.2 acoustic transducer A component that produces either an acoustic output in response to an electric stimulus and/or an electric output in response to an acoustic stimulus. 3.3 axial flow velocity The component of liquid flow velocity at a point in the measurement section that is parallel to the measurement section’s axis and in the direction of the flow being measured. 3.4 flow-conditioning element A device for reducing swirl and velocity distortions. 3.5 K-factor pulses per unit volume. 3.6 meter run The section of piping which includes the upstream flow-conditioning section, the flow meter and the downstream flow section. 3.7 pulse scaling Scaling performed in the SPU so that the meter produces a set number of pulses proportional to volume. 3.8 SPU signal processing unit Electronics system, including power supplies, microcomputer, signal processing components and ultrasonic acoustic transducer excitation circuits, may be housed in one or more enclosures mounted locally or remote to the meter. 3.9 transit time Measurement of the time interval associated with transmission and reception of an acoustic signal between acoustic transducers. 3.10 UFM ultrasonic flow meter. 4 Design Considerations 4.1 The design of an Ultrasonic Flow Meter (UFM) run shall take into account the following considerations. 4.1.1 The meter run design shall consider the user’s minimum and maximum flow rates, Reynolds number, temperatures and pressures. Additionally, it shall consider the following physical properties; viscosity, relative density, vapor pressure, and corrosiveness. Operating within the linear flow range of the UFM based on the specific application is desirable. 4.1.2 Temperature devices, temperature test thermowells, pressure and density sensing devices shall be installed to accurately represent the actual metering conditions. Immediately downstream of the meter run is the preferred location (see Figure 1).
4.1.5 The meter run design shall ensure that each meter is liquid filled under all operating conditions. Placement of the meter(s) at high points in the system shall be avoided. UFMs may be installed in any position or plane. However, care shall be taken to ensure that the acoustic transducers are not located on the top or bottom of the pipe to minimize the effects of air or sediment. The meter’s installation orientation should be in accordance with the manufacturers’ recommendation. 4.1.6 For multiple meter runs, see MPMS Chapter 6 (all sections) for meter system design considerations. 4.1.7 Steps shall be taken to minimize the amount of water in the fluid being measured. Depending on the flow regime, the acoustic properties of the oil, the water droplet size and distribution, and the amount of water, UFMs may become less accurate because paths may become inoperable. Due to the number of possible variables, a specific % water limitation cannot be given. Consult the UFM Manufacturer for guidance on this limit. The meter diagnostics may be useful in understanding the performance of the meter. See Section 12. 4.1.8 The design shall comply with all applicable regulations and codes. 4.1.9 Meters shall be adequately protected from excessive pressure through the proper use of pressure relief devices. This kind of protection may require the installation of surge tanks, expansion chambers, pressure-limiting valves, pressure relief valves, and/or other protective devices. 4.1.10 The operating pressure in the meter run shall be maintained sufficiently above vapor pressure.