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

Page 75 of 114

74 | P a g e

of water into the barge tank being calibrated and recording the height of the liquid above
datum in the tank or any other method as approved by Director of Petroleum Resources.
2.7.4 Frequency of Calibration
All storage vessels/tanks shall be calibrated before being put into operation and
subsequently after five operational years or after any maintenance work necessitating
changes to the deadwood of the tanks in the form of size, number and arrangement.
2.7.5 Applicable Standard
This shall be API MPMS 2.8A, API Standard 2553 or ASTM –D1407 under title “Measurement
and Calibration of Barges”.
2.7.6 Calibration Equipment
The basic and accessory equipment shall be as specified in the reference standards and shall
comply with the specifications stipulated therein.
2.7.7 Calibration Procedure
2.7.7.1 Each tank shall be thoroughly cleaned prior to calibration and water shall be used as
the calibrating liquid. The shore tank containing the calibrating liquid shall itself must
have been calibrated in accordance with Part III Section 2.5 of this guide and in which
details of the approved procedure for calibrating vertical cylindrical tanks has been
outlined.
2.7.7.2 Liquid draw from the shore tank shall be by gravity drive. However, if the storage
vessels are to be calibrated using meters, then the measurement procedure shall be
as stipulated in API Standard 2555, ASTM D-1406 and API MPMS Chapter 5.2. The
procedure outlined in reference standard shall be generally followed to obtain the
internal tank measurements, temperature and gravity parameters, linear deck
measurements and deadwood measurements.
2.7.7.3 Calculation of the barge tank capacity and incremental volume shall be made in
accordance with the steps outlined in the reference standard.
2.7.8 Presentation of Results
2.7.8.1 The field data to be submitted along with the calibration chart of each tank in the
storage vessels shall contain the following information:
a)
Name of storage vessel.
b)
Name and address of operating Company.
c)
Name and address of calibrating company.
d)
Name of builders of the storage vessel, the date of construction and date of
last calibration of tank.
e)
Nominal capacity.
f)
Compartment or tank number.
g)
Total height.
h)
Linear measurements.
i)
Deadwood description.
j)
Gross Volumes.

2.7.8.2 The calibration chart shall be prepared showing the incremental net volumes at 60ᵒF
with appropriate indication of the total under deck cargo capacity.