Pipe Purging Using CMS Nitrogen Generation

What is CMS PSA Nitrogen Generation in Pipe Purging?

When new pipelines are built or repaired, removing air, moisture, and volatile gases is essential before transporting products. Therefore, engineers use high-purity nitrogen, typically 99.999 % with a dew point below -60 °C, because it is inert, non toxic, and easily produced on-site with a carbon molecular sieve PSA system. This nitrogen stops flash rust on carbon steel and prevents explosive mixtures when hydrocarbons are present. Additionally, it keeps weld roots bright and oxide free and ensures the first product is not contaminated by trapped oxygen or moisture. On-site CMS PSA units deliver ultra dry nitrogen continuously. Consequently, they eliminate tanker deliveries and give engineers real-time purity data to confirm every purge meets safety and GMP requirements.

How Pipe Purging work with Carbon Molecular Sieve PSA Nitrogen Generation?

• Pipe Isolation and Preparation: Depressurize and isolate the pipeline using blinds or valves.
• Nitrogen Introduction: High-purity, ultra-dry nitrogen from a CMS PSA generator, introduced at the lowest point of the pipeline. Consequently, it pushes air and moisture out through a vent at the highest point.
• Continuous Monitoring: The system continuously measures oxygen levels and dew point during the purge. Purging continues until oxygen drops below 1% and dew point is consistently below –60 °C.
• Final Pressurization or Venting: Once target levels are met, operators either vent the pipe for safe maintenance or welding, or maintain it under slight nitrogen pressure until startup, preventing oxygen and moisture from re-entering.

Benefits of High Purity Nitrogen for Pipe Purging

• Safety: Nitrogen drives the oxygen level inside the pipe below the combustion point, so workers can perform hot work without risking fire or explosion.
• Bright, defect free weld roots: An oxygen free purge keeps the molten root surface from forming scale or porosity, giving a smooth, strong weld that needs no post weld grinding or pickling.
• Corrosion protection from day one: Dry nitrogen (dew point about -60 °C) removes oxygen, preventing flash rust on carbon steel and pitting on stainless pipe interiors.
• Single gas, multiple tasks: After purging, the same nitrogen line pressurizes the system for leak testing and then dries or inert the pipe during storage, so one gas service streamlines the work.

Why use High Purity Nitrogen for Pipe Purging?

• Prevents Oxidation and Rust: Stops oxidation and flash rust inside carbon steel pipelines, preserving coating quality and preventing initial corrosion.
• Eliminates fire and explosion risk: when welding or opening hydrocarbon lines the oxygen content never reaches the lower flammability limit.
• Ensures Product Purity: Prevents contamination from trapped air and moisture, ensuring pipelines deliver clean.
• Energy Efficient Drying: Removes residual moisture quickly and efficiently with ultra dry nitrogen, reducing the need for energy intensive hot air drying methods.
• Easily verified: oxygen and dew point analyzers give real time proof that the purge is complete.