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API MPMS 5.3 2005 pdf free download

API MPMS 5.3 2005 pdf free download.Manual of Petroleum Measurement Standards Chapter 5—Metering Section 3—Measurement of Liquid Hydrocarbons by Turbine Meters. For severe swirl, such as generated by two close coupled elbows out-of-plane (i.e., non-symmetrical swirl) or by a header (i.e., dual symmetrical swirl), a straightening ele- ment (i.e., swirl breaker) type of flow conditioner is required. These types of swirl are slow to dissipate in straight pipe, often existing after 100+ diameters of straight pipe. A straightening element or swirl-breaker type of flow conditioner usually consists of a cluster of tubes, vanes, or equivalent devices that are inserted longitudinally in a sec- tion of straight pipe (see Figure 2). Straightening elements effectively assist flow conditioning by eliminating swirl. Straightening elements may also consist of a series of perfo- rated plates or wire-mesh screens, but these forms normally cause a larger pressure drop than do tubes or vanes. Proper design and construction of the straightening element is important to ensure that swirl is not generated by the straightening element since swirl negates the function of the flow conditioner. The following guidelines are recom- mended to avoid the generation of swirl: a. The cross-section should be as uniform and symmetrical as possible. b. The design and construction should be rugged enough to resist distortion or movement at high flow rates. c. The general internal construction should be clean and free from welding protrusions and other obstructions. Isolating type flow conditioners, which produce a swirl-free, uniform velocity profile, independent of upstream piping configurations, are typically more sophisti- cated, expensive and higher pressure drop than simple straightening element type flow conditioners. However, in certain installations, they provide a performance advantage and should be considered. Flanges and gaskets shall be internally aligned, and gaskets shall not protrude into the liquid stream. Meters and the adjoining straightening section shall be concentrically aligned. PRESSURE CHANGES If the pressure of the liquid when it is metered varies from the pressure that existed during proving, the relative volume of the liquid will change as a result of its compressibility. (The physical dimensions of the meter will also change as a result of the expansion or contraction of its housing under pressure.) The potential for error increases in proportion to the difference between the proving and operating conditions. For greatest accuracy, the meter should be proved at the oper- ating conditions (see API MPMS Chapters 4 and 12). Volumetric corrections for the pressure effects on liquids with vapor pressures above atmospheric pressure are refer- enced to the equilibrium vapor pressure of the liquid at the standard temperature, 60ºF, 15ºC, or 20ºC, rather than to atmospheric pressure, which is the typical reference for liq- uids with measurement temperature vapor pressures below atmospheric pressure. Both the volume of the liquid in the prover and the registered metered volume are corrected from the measurement pressure to the equivalent volumes at the equilibrium vapor pressure at the standard temperature, 60ºF, 15ºC, or 20ºC. This is a two-step calculation that involves correcting both measurement volumes to the equivalent vol- umes at equilibrium vapor pressure at measurement tempera- ture. The volumes are then corrected to the equivalent volumes at the equilibrium vapor pressure at the standard temperature, 60ºF, 15ºC, or 20ºC. A detailed discussion of this calculation is included in API MPMS Chapter 12.2.

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