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GUIDE FOR THE ESTABLISHMENT AND OPERATIONS OF DOWNSTREAM GAS FACILITIES IN NIGERIA (LPG, CNG, LNG) ISSUED BY

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Applicable to all Oil & Gas Operators  
GUIDELINES FOR THE ESTABLISHMENT AND OPERATIONS OF CNG 
COMPRESSION FACILITIES IN NIGERIA 
Code: DPR Guide 0029 - 2020 
 
Revision  Date: 1st September 2020 
 
 
 
This is a property of the Department of Petroleum Resources. All rights reserved  
 
14 
iv. All safety valves shall be fitted with vent pipes discharging vertically upwards at a 
minimum height of 2 meters above the rank top.  The vent pipes shall be fitted with 
loose fitting rain caps. 
v. Every CNG storage unit including each manifold group of cylinders or bulk storage 
tank shall be provided with suitable pressure gauges which shall communicate 
directly with the tank or storage unit system and shall have an opening not to 
exceed 1.4 mm diameters at the connection.  The pressure gauge shall have a dial 
graduated to read approximately double the operating pressure, but in no case less 
than 1.2 times the pressure at which the pressure relief valves is set to function. 
Pressure gauges shall be checked and calibrated at intervals not exceeding 12 
months in line with MOSR 1997. 
vi. Methane gas leak detection device shall be provided at the CNG facilities for 
warning when an airborne methane gas concentration exceeds 20% of the lower 
explosion limit, warning shall be plainly audible and visible to those within the zone 
of potential exposure to fire or explosion of vessel, system or delivery operation. 
vii. Multiple cylinder units or groups stored in the vertical position shall be limited to a 
width of no more than 4 cylinders. Units or groups stored in the horizontal position 
shall be limited to a height of 6 cylinders at a width of 4 cylinders. When stacked 
horizontally, the units or groups shall be separated by not less than 1.5 meters. 
3.5 
Facility Connecting Pipework and Valves 
Piping, Valves and fittings are to be fabricated, installed, and tested inline with 
international standard such as ASME Process Piping Code or any other applicable codes 
recognised by DPR.  Any exterior piping shall be buried or installed above ground and shall 
be supported and protected against mechanical damage. Additionally, the following shall, 
at a minimum, apply: