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

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1.8 Orifice Plate Installation Straight Run Requirement with Flow conditioners 
Minimum straight run lengths for orifice runs and other flow elements shall be in 
accordance with ISO 5167-2 and installation of flow conditioners as recommended in API 
MPMS 14.3.2/AGA report No.3 Part 2. 
1.9 Inspection and Maintenance 
The orifice meter shall be validated at least on quarterly basis and the exercise shall be 
witnessed by a DPR representative. The validation exercise shall involve the following: 
i. 
Orifice plate visual inspection – measurement of the orifice bore diameter 
(dm), pipe inside diameter (Dm), Orifice outside diameter (D), orifice 
thickness and the departure from flatness. The maximum allowable 
departure from flatness shall be 0.005(Dm – dm)  
ii. 
Calibration of field instruments -flow transmitters, pressure transmitters, 
temperature sensors, Gas chromatograph, densitometers, flow computers 
in line with their footprint certificate 
iii. 
The physical instruments – temperature probe, resistors, voltmeters, 
pressure gauge, used in the calibration exercise must be tagged with details 
of the calibration date and due date, and the certificates must be valid and 
made available for sighting by the DPR representative. 
A 
HEADER 
DETAILS 
STATUS 
1 
Company name 
 
 
2 
Date of Inspection 
 
 
3 
Name of Inspector(s) 
 
 
B 
GENERAL INFORMATION 
 
 
1 
Serial number 
 
 
2 
Nominal Pipe diameter 
 
 
3 
Fluid 
measured 
(gas/liquid) 
 
 
4 
β ratio limit 
 
 
C 
METER TUBE 
 
 
1 
Type of orifice holder 
(flange/fitting) 
 
 
2 
manufacturer 
 
 
3 
Serial number 
 
 
4 
Flow 
conditioner 
(Yes/No) 
 
 
5 
Type of flow conditioner 
 
 
6 
How 
fastened? 
(welded/flanged/pinned) 
 
 
7 
Dimensions  
Length: 
 
Upstream diameter: 
Downstream diameter: 
First pipe connection: 
Second pipe connection: 
Upstream pressure tap: 
Downstream pressure tap: 
8 
Meter run type 
 
 
9 
Meter tube temperature