Internal Coating Rehabilitation

Internal pipeline coating in the field as well as internal coating rehabilitation are a relatively new but extremely effective solution.


scheme of internal coating rehabilitation


Pig launchers and receivers are used for internal coating application, and they can be spaced as far apart as 48km.


pig launcher

pig receiver


Work is done in several stages:


1. internal surfaces
of the pipe are mechanically cleaned with a cleaning pig,


placing of cleaning pig in pipe

cleaning pig after passing through the pipe


2. chemical cleaning and preparation of the surface is carried out to improve the coating adhesion:

  • activation of the surface with etching solution contained between two consecutive pigs,
  • drying of internal pipe surface using separate pig;

placing of drying pig


3. application of internal coating by deposition of a special coating solution contained between the second pig from stage 2, and a third pig.


placing pig in pipe
for internal coating application


As a result, not only is the service life of the pipeline increased,
but its throughput is improved as well, since internal deposits
and friction are eliminated, thereby lowering the resistance.


rehabilitated internal coating


Over the past few years, low–pressure lines (mostly in city infrastructure) have been successfully repaired
by pulling a polymer pipe through an existing pipeline.


The polymer pipe is slightly smaller in diameter than the existing pipe. Tightly gripping the new line, the old one now serves as mechanical protection.

The insignificant decrease in diameter is compensated
for by increase in throughput due to lower resistance and leakage.


a polymer pipe relining an old pipe

If the existing pipe is made of material that can be destroyed by specific vibrations, the polymer pipe replaces the old pipe, which it destroys as it is pulled through.


replacing pipe by destruction of the old pipe


Trenchless methods are used on these jobs, which is important for cities and busy highways.