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Applicable to all Oil & Gas Operators GUIDELINES FOR THE DESIGN, CONSTRUCTION, OPERATION AND MAINTENANCE OF OIL AND GAS PIPELINE SYSTEMS IN NIGERIA Code: DPR Guide 0027 – 2021

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Applicable to all Oil & Gas Operators  
GUIDELINES FOR THE DESIGN, CONSTRUCTION, OPERATION AND 
MAINTENANCE OF OIL AND GAS PIPELINE SYSTEMS IN NIGERIA  
Code: DPR Guide 0027 – 2021 
 
Effective Date: 14th October 2021 
 
This is a property of the Department of Petroleum Resources. All rights reserved  
 
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pressures. The test result shall be lodged with the nearest office of the 
Department. 
iii. 
Pipelines laid in densely populated areas shall be tested ONLY with water up to a 
minimum of 140 percent of their design maximum operating pressures and the 
test result shall be lodged with the nearest DPR office.  
iv. 
Leak test shall however be performed on the pipeline system with the use of 
pressurized air or gas between 100 PSI to 20 percent of the minimum specified 
yield of the material for pipelines that has been designed to withstand 20 percent 
or more of the specified minimum yield strength.  
v. 
Pipeline to be operated below 100 PSI shall be subjected to a leak test at 
maximum system pressure. 
vi. 
Any gas pipeline that will not be put into use for more than six months after 
construction shall be filled with inert gas or nitrogen and if it is to be put into use 
after one year of completion shall be pressure tested and certified by an official 
of Department of Petroleum Resources before being put into use. 
vii. 
Gas pipeline systems shall be well purged with water, air or inert gas before 
undertaking any repairs and the environment of the repair site shall be constantly 
monitored with gas detecting device to ensure adequate safety. 
4.3 Gas Pipelines Made with Materials Other Than Ductile Steel   
4.3.1 Cast Iron Materials 
Cast iron Materials shall be used for gas pipelines under specified application to and with 
special approval by the Department. Such applications shall be supported with the 
compelling reasons for using Cast Iron Material. However, the design considerations shall 
strictly follow the specifications in paragraph 842 of ASME B31.8-2018 and other 
internationally recognised standards approved by DPR. 
4.3.2   Plastic Materials   
The use of thermoplastic and thermosetting plastic materials of the grades specified in 
ASTMD 2513 and ASTMD 2517 shall be generally allowed for laying service lines only. 
i. 
The design pressure for plastic gas piping system shall be governed by the 
formula given in reference standard ASME B31.8-2018 where the value of the 
plastic design factor shall not be less than 0.32 for any case.