© 2019 Department of Petroleum Resources. All rights reserved Department of Petroleum Resources (DPR) PROCEDURE GUIDE

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2.6.3 Approved Meter Proving Procedure
2.6.3.1 The standard device approved for meter proving shall be the bi-directional or uni-
directional pipe Prover. However, tank provers and master meters shall be accepted
on case basis.
2.6.3.2 A representative of the Department of Petroleum Resources shall always be present
during any proving exercise. In conducting a proving run for pipe Prover, master
meter or tank Prover, all steps outlined in API MPMS 4 and 12 or its equivalent
standards shall be followed, and the results shall be presented as indicated by the
example in Appendix V for a pipe Prover proving run.
2.6.3.3 In case where proving has been by tank Prover or master meter method, the
procedure outlined in the reference standard shall be closely followed in carrying out
the proving and presenting the results.
2.6.3.4 The following requisite steps must be adhered to before Meter Proving:
a) The entire fluid stream from the meter to be proved is diverted to flow through the
prover, care being taken to ensure that there are no leakages from the valve
assembly as this may lead to erroneous results. Flow is maintained through the
meter and the prover section until stable conditions of temperature and pressure
are reached.
b) Entrained air or vapour shall be removed from the pipeline connections and the
prover by venting at suitable points (usually the highest points of the Prover pipe).
c) The two detector switches which demarcate the calibrated section of the Prover
loop are also connected to the electronic counter by means of an electric cable.
d) The electronic counter is then plugged to a power source.
e) The electronic counter shall be tested for its repeatability which must not exceed
a difference of ±0.0002. This test is achieved by switching on the “TEST” button of
the electronic counter. When the button/switch is on, the counter should
intermittently register 1,000 counts (pulses). These counts should check to within ±2.
f) Calibrated pressure gauges and thermometers of appropriate types shall be
mounted at both the inlet and outlet sections of the Prover loop.
g) Flow rate shall be noted to be constant and within the designed range. This is
achieved using a stop watch to repeatedly time the liquid flow through the meter.
h) The back pressure down-stream of the meter shall be maintained at the
manufacturer’s recommended figure to ensure that there is no cavitation or
excessive swirling in the vicinity of the meter.
i) Trial proving run shall thereafter be conducted as a final check before the
commencement of a recorded meter proving.
2.6.3.5 Proving Run
a) The ball is launched by operating the appropriate Prover valves. The ball should
move into the flowing stream from the housing tee, and be swept into the Prover
loop section