Introduction
Running ILI equipment in oxygen pipelines imposes strict chemical compatibility and safety requirements. The presence of smallest quantities of organic residues or contaminants can pose a significant risk of spontaneous combustion/explosion during post maintenance start-up.
Before running ILI in oxygen pipelines, it’s mandatory to carry out a deep cleaning on all equipment to avoid ignition of components. The presence of the smallest quantities of organic and inorganic materials like oil and grease graphite can cause a significant risk of spontaneous combustion during the start-up of the pipeline.

Purpose of the study
The aim of this paper is to describe the relevance of a proper cleaning & degreasing process before inspecting transportation oxygen pipelines.

Regulations
EIGA Doc 33, Cleaning of Equipment for Oxygen Service

Methodology

1. Pig preparation
The tool is made of oxygen-compatible metallic and polymeric materials, is disassembled and undergoes a mechanical and oil-free compressed air pre-cleaning phase to remove particulate and visible residues.

2. Chemical degreasing

Solvent frequently used is acetone, an organic solvent with high volatility and degreasing power, applied by immersion/brush/removing oils/silicones.

3. Drying and Degasification
Each piece undergoes a drying cycle in a forced convection air environment.

4. Inspection methods
Wipe tests and Wood's lamp are used for final cleaning verification with UV radiation, making invisible contaminants visible, i.e. organic and fatty residues.

Results and Conclusions
The described protocol has been developed and consolidated in several ILI operations and has confirmed being highly effective and successful in preparing tools for oxygen pipelines. The use of chemicals and mechanic tools ensure the removal of any organic contaminants, while Wood's lamp and white cloth verification allows for fast and reliable quality control. This approach complies with the safety standards, reducing the risk of unwanted reactions and improving the operational longevity of both pipelines and inspection tools.