Home>API>API MPMS 12.2:1981(2002) pdf download

API MPMS 12.2:1981(2002) pdf download

API MPMS 12.2:1981(2002) pdf download.Manual of Petroleum Measurement Standards Chapter 12—Calculation of Petroleum Quantities Section 2—Calculation of Liquid Petroleum Quantities Measured by Turbine or Displacement Meters.
In some metering appliocs, the variables MF and C,.., in Equation 17 ate combined into a “composite rne factor.” When such a composite meter factor is applied to the indica volume of a 1enu compensated meter (which a tomancally applies CJ, the metered quantity in barrels at sdard conditions can be obtained by multiplying indicated volume by the composite MF alone.
h is important not to confuse a standard me factor (Equation IS) with a composite meter factor. They are nor interchangcable. HIERARCHY OF ACCURACIES
Meter factors fit into the hierarchy of accuxacies between calibrated prover volttny4 (12.2.6) and calculation of measuxPm tickets (12.2K). Thus tern itu readings for proving should be averaged and then rounded to the ueat 0.5’F. Pressuxe re.iingt for proving should be averaged and then rounded to the est scale division, a pressuxe gage with its appropriate range having previously been selected. RULE FOR ROUNDING—Utiji FACTORS
In calatl21ng a meter factor, demine d numerator and ‘v.m.kii values separately, with each rouni to at — five signthcatxt digits. In intermediate calculations individual cormection fars to four decimal places. Multiply individual correcuce factors together, rounding to four iInI plates at each step (for each matcr and denominator), and record the comb carrecoon factor (CC!) rounded so four decimal places. Divide coincied prover volume by corrected meter volume, and round the resulting meter factor to four decimal places.
m”- by reading the upper gage glass ci the tank; itat indicated volume should be recorded to the resz thousandth of a barrel. If the botsom gage glass was
at o before the proving run was started, its rending must be 4’4ed so or uxbaacmed from (as the case may be) the up gage glass reading, and the algebraic sum recorded as d indic4 volume.
To akulate a m factor, both prover and meto vol.
Two runs are shown in the example. for each of which a run meter factor calculation is made separately: the two results are then averaged, the result obtained sometimes being called the meter factor to be used.’ Note that this procedure differs from that employed with a pipe prover in which pulses. temperature. and pressure are averaged, and the meter factor is calculated from the average values of pulses. temperature. and pressure (see 12.2.7). CALCULATION OF ThE METER
Turbine meters and pipe provers were developed after displacement meters and tank provers: therefore. the procedure for calculating a meter factor for a turbine meter proved against a pipe prover was generally modeled on older procedure, but some changes were made.
Because a pipe prover is subject to die effects of both temperature and pressure on the steel, its base volume (which is at standard conditions) has to be corrected to obtain its volume at proving conditions. The volume of the displaced liquid must then be corrected to the equivalent volume at standard temperature and pressure. This latter value becomes the numerator in Equation 15 and the corrected meter volume becomes the denominator. For this procedure to be applied, the displacement meter must have a high resolution electrical output. that is. a Large number of pulses per barrel so that at least 10.000 pulses or their equivalent are obtained.
The other rules and conventions discussed in apply to calculation of a meter factor using a pipe prover and a turbine meter.


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