Overthrust Pipeline Company
First Revised Volume No. 1-A
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Effective Date: 11/01/1997, Docket: RP97-131-005, Status: Effective
Second Revised Sheet No. 61 Second Revised Sheet No. 61 : Superseded
Superseding: First Revised Sheet No. 61
value based on cubic meters, the reporting standard is
megajoules/cubic meter at standard conditions of 101.325
kPa, 15 degrees C, and dry. (For reference, one megajoule
equals one million joules.) Overthrust will standardize the
reporting basis for gas volumes as cubic foot at standard
conditions of 14.73 psia, and 60 degrees F. For gas volumes
reported in cubic meters, the standard conditions are
101.325 kPa and 15 degrees C.
13.2 Atmospheric Pressure. For the purpose of
measurement, calculation and meter calibration, the average
absolute atmospheric (barometric) pressure shall be based on
the actual altitude at each point of measurement
irrespective of variations in natural atmospheric pressure
from time to time. When electronic computer measurement is
used, the gas pressure will be measured directly, using a
pressure measuring device for continuous input to the
electronic computer.
13.3 Temperature. The temperature of the gas will
be determined at the points of measurement by means of a
properly installed recording thermometer or continuous
electronic transducer input to a computer of standard
manufacture selected by Overthrust and installed according
to the recommendations contained in ANSI/API 2530 (Orifice
Metering of Natural Gas). The arithmetic average of
temperatures for each day shall be used in computing
temperatures of the gas during such day for conventional
chart measurement. When electronic computer measurement is
used, average daily temperature will be computed as a
running average.
13.4 Determination of Gross Heating Value and
Specific Gravity. Since Overthrust has installed electronic
computer measurement equipment and field chromatographs, the
determination of gross heating value and specific gravity
shall be made from the composition by calculation using
physical gas constants for gas compounds as outlined in GPA
Standard 2145 92 and GPA Standard 2172-86 (Table of Physical
Constants of Paraffin Hydrocarbons and Other Components of
Natural Gas) with any subsequent amendments or revisions
that Overthrust may adopt.
If Overthrust elects to install conventional chart
measurement, the arithmetic average of the hourly heating
value and specific gravity recorded during periods of flow
each day by a recording calorimeter and gravitometer or
recording chromatograph, if installed, will be the gross