Micro Motion Guide: Guidelines for Troubleshooting and Operation of Provers with ELITE Coriolis Flow Meters | Micro Motion Manuals & Guides

Reference Guide

MC-002152
2/2018

ELITE® Coriolis Flow Meters

Guidelines for Troubleshooting and Operation
of Provers with Micro Motion ELITE

®

Coriolis

Flow Meters

Micro Motion® ELITE® ow meters are high-

precision Coriolis ow meters that are often used
in the oil and gas industry in conjunction with
volume provers. These guidelines are designed
to aid in troubleshooting and operation of provers
that are in use together with Micro Motion Coriolis
meters. Proving results may vary if unstable

process conditions exist during proving.

Proving Methods and Proving Data Evaluation

The American Petroleum Industry (API) Manual
of Petroleum Measurement Standards (MPMS)
Chapter 4.8, Second Edition, Operation of Proving
Systems, Annex A, Evaluating Meter Proving
Data explains the relationship between the number

of proving runs, the observed repeatability, and the
random uncertainty of the resulting meter factor.
One important principal is that a lower meter factor
uncertainty will always result as more runs are
collected and averaged.

Prover Size and Selection for Fixed-Volume
Provers (Does Not Apply to Master Meter
Provers)

Important Note: The prover size should never
result in a pass time of less than 0.5 seconds or
a pre-run time of less than 0.25 seconds.

Prover Conditions

It is important to prove at conditions that are as
similar as possible to the expected operating
conditions. There are many conditions and factors

that can inuence the success of proving systems.

• Prover equipment and all supporting reference
measurement devices must be well-maintained

and veried to ensure measurement traceability,

reproducibility, and repeatability (API MPMS
Ch. 4 and Ch. 21.2, paragraph 2.11).

• Stability of ow rate, density, temperature, and

pressure is critical during proving. System design,
prover settings, and maintenance can all impact

ow rate stability during proving.

• The liquid inside the piping connecting the meter
to the prover should remain stable.

o

Minimize piping between the meter and

prover.

o

Avoid dead-end branches between

meter and prover that may act as a volume

“spring” with compressible uids.

Increasing the Base Prover Volume (BPV) will result in
passing repeatability requirements with fewer prover
passes. Increasing the number of passes will allow
for passing repeatability requirements with a smaller
prover. A decision may be made either to size the
prover with a smaller BPV (lower capital investment)
with a longer overall proving time, or with a larger BPV
with reduced runs (less long-term wear and tear) and
shorter overall prove time.

www.Emerson.com/MicroMotion

Reference Guide

MC-002152
2/2018

ELITE® Coriolis Flow Meters

• Flow pulsation from PD pumps, including lack
of back-pressure regulation, may inuence

repeatability and additional passes may be
needed to meet random uncertainty requirements.

• Enabling compensation for the effect of pressure
on the meter (consult the Transmitter Congura­tion and Use Manual) can improve repeatability
in applications where line pressure varies by more
than 30 psig during proving runs.

Meter Operation

When using smaller provers, it is important to

ensure that the meter is congured for optimum
ltering and speed of response.

1. Select the fastest speed of response available:

o

5700 transmitter: select “Low Filtering”

response mode

• Sufcient back pressure must be maintained on

both the prover and the meter to avoid vapor

breakout and to maintain a stable ow rate during

displacer launch and travel. Minimum recom-

mended back pressure is shown by Equation 4

(from API MPMS Ch. 5.6).

Equation 1: ρb ≥ 2 Δρ + 1.25 ρ

e

Where: ρb = Minimum back pressure (psig)

Δρ = Pressure drop across meter at max.

ow rate

ρe = Equilibrium vapor pressure at

operating temperature (psia)

• Accurate prover density measurement is crucial
when mass proving with a volumetric prover. The
following tolerances are advised when using a
pycnometer (API MPMS Ch. 14.6).

o Max. temperature difference = 0.2 °F

o Max. pressure difference = 1 psi

o Density Meter Factor (DMF) repeatability

should be 0.05% or better between consecutive
pycnometer tests

o

2700 transmitter: select “Special” for Update
Rate and either “Special” or “Low Filtering”
for Calculation Speed

2. Set ow damping to a value between 0.0 and

0.08 seconds.

3. Set density damping to 0.16 seconds.

4. Proving Wizard software is available from
Emerson to aid in preparing Micro Motion
Coriolis meters for proving

When the meter factor remains stable between
proving events, this indicates that the meter zero
setting value is good. A change in the meter factor
may or may not be related to the meter zero, so it is

important to always perform a Zero Verication Test
(consult Transmitter Conguration and Use manual)
before making any zero adjustments. Only adjust
the meter zero if advised to by the Zero Verication
Test. If a meter zero is adjusted, reprove the meter.

Coriolis ow meters do not have a xed K-factor
(number of pulses output per unit of ow). The
number of pulses output per unit of ow (e.g. pulses
per barrel) from a Coriolis meter is an adjustable

parameter that can be set to any desired value.
However, the frequency of pulses during the highest
ow rate must not exceed the pulse input capacity
of the prover pulse counting device.

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