API RP 5L2:Specification Of Inter Liquid Epoxy Coating For Pipeline

API RP 5L2:Specification of inter liquid epoxy coating for pipeline


Last article, we explained Why Internal Coating Is Necessary For Oil And Gas Pipeline? Now the most widely used internal anti-corrosion options are Liquid epoxy coating and Fusion Bonded Epoxy (FBE). Liquid Epoxy resin flow-coat linings have established themselves as standard practice in this application. Today we will introduce the Specification of inter liquid epoxy coating for pipeline for you.


Liquid epoxy coating is a coating system composed of two substances which is applied in a single coat as anticorrosion protection for steel pipes. The first process the pipes go through are cleaning & blasting. Then liquid epoxy is applied to the pipes inner surface by spray guns in a bogey, forming a uniform single layer epoxy which cure after application.


API RP 5L2 (DIN EN 10311), standard which provides for the internal coating of line pipe used for non-corrosive natural gas service. API RP 5L2 cover 5 sections for the application of internal coatings on new pipe prior to installation. 

Section 1 Scope

Section 2 Coating Material Specification,Section 3 Laboratory Coating Testing  

Section 4 Application Practices

Section 5 Production Inspection and Acceptance The Recommendation is limited to the application of internal coatings on new pipe prior to installation.


The main performances of inter coating according to API RP 5L2


Performance Index

Test method

Pinhole test

Pinhole dispersion shall be held to a minimum

API RP 5L2-2002

Dry film thickness

2.0 ± 0.2 mils((51 ± 5 micron)

API RP 5L2-2002

Cure lest

No softening,wrinkling or blistering

API RP 5L2-2002

Adhesion test

No loss or adhesion

API RP 5L2-2002

Bend test

No loss of adhesion,spalling,crack

API RP 5L2-2002

Soaking test

no loss of adhesion,softening,wrinkling or blistering

API RP 5L2-2002

Stripping test

flake off,present powder particles when rolled

API RP 5L2-2002


The internal coating is applied in liquid or powder form on steel pipes used for oil, gas, water, industrial and corrosive fluids, etc. The benefits of liquid epoxy coating including: economic efficiency compared with other forms of coating;As a coating and filler, it can be easily applied to uneven surfaces.It is waterproof and resistant to various elements such as acid, rust, chemistry, corrosion and heat.


Liquid epoxy coating provide a thermoset end-product with a unique combination of properties.WORLD IRON&STEEL 3LPE and 3LPP pipeline is compliance with all major international standards such as API RP 5L2,Any needs,call for us today!