HYDROCARBON
ENGINEERING
73
F
or inventory control and custody transfer
of petroleum products for tank storage,
using a metering system is considered the
best measurement practice. Metering
systems provide superior measurement accuracy,
verifiable reliability, and increased utilisation, all of
which provide accountability for custody transfer
and can make metering financially beneficial and
more cost effective than other kinds of
measurement, such as tank gauging.
The basics
A metering system is made up of several
components, at the heart of which is the meter.
There are several different kinds of metering
technologies, including positive displacement (PD),
turbine, Coriolis or ultrasonic meters. Each uses a
different method of metering, from the PD meter’s
direct, volumetric measurement to an ultrasonic
meter’s use of transit time measurements to
calculate product flow. Each has its advantages for
different kinds of applications. Every meter
measures volume of product during operation: they
measure product that’s being transferred into or out
of volumetric based storage tanks.
In addition to the meter, a metering system
consists of different kinds of metering accessories.
Pressure and temperature transmitters, for example,
METERING
SYSTEMS
VERSUS TANK
GAUGING
