Scope
This Guideline provides a method to ensure that the stream flow calculation
is functioning correctly by injecting simulated flow signals.
Frequency As required
Procedure PREPARATIONS:
Ensure that the meter stream is off-line and out of service.
Give a brief description of the test in the Metering Log Book.
Record the results of the test on the Flow Rate Computation Check
Test Sheet, attached
Verify that the certificates for the test equipment are valid. Check
that the test equipment serial numbers and certification dates are
accurately recorded on the test sheet and correspond with the test
equipment used. Ensure the flow computer tag and serial numbers
are recorded on the test sheet.
CALIBRATION EQUIPMENT:
A) Frequency Generator
B) Frequency Counter / Timer
PROCEDURE:
The stream flow rate calculation shall be checked using the following
procedure: –
a) Liaise with Operations department to zero the stream flow
computer or record the stream totals, as appropriate.
b) Disconnect the turbine meter field input. Connect the turbine
meter simulator to the turbine meter input.
c) Connect the timer counter across the output of the turbine
meter simulator. The timer/ counter should be set up to
measure frequency.
d) Adjust the frequency at which the pulses are fed into the flow
computer in order to not exceed the pre-set high and low
alarms for flow rate.
e) Note the values of gross volume flow rate at three different
input frequencies.
f) Complete the flow rate computation test sheet. If the
calculated and actual flow rates are within tolerance the test is
complete. The flow computer should be returned to the ‘As
Found’ state with the fixed line density, reference density, and
temperature and pressure values removed from use.
g)
If the calculated and actual flow rates are out of tolerance
investigate the reason and attempt corrective action. If a
significant error is still observed, change the flow computer.
h) Once the calculated and actual flow rates are within tolerance
complete the test sheet and ensure it is marked with
appropriate comments. The test is complete, return the flow
computer to the ‘As Found’ condition with the fixed line density,
reference density, temperature and pressure values removed
from use.
o) Enter details of all tests in the Metering Log Book. Record if the
flow computer has computer has been replaced and the serial
number of the replacement flow computer.
FLOW RATE COMPUTATION TEST SHEET
