Services
Nitrogen Purging & Preservation Services
Efficient, industry-certified nitrogen purging solutions for oil, gas & energy projects.
MCCS delivers complete end-to-end nitrogen purging and preservation solutions designed to remove moisture, oxygen and contaminants from process lines and keep your systems safe, inert, and operationally stable.
Backed by over 30 years of experience delivering major international offshore and onshore services, MCCS provides high-integrity nitrogen purging and preservation services that meet stringent international safety and operational standards.
What Is Nitrogen Preservation?
Nitrogen preservation is when inert nitrogen gas is pumped into petrochemical piping systems and equipment to prevent oxidation, corrosion, and contamination during extended periods of inactivity, including during periods of construction, offshore maintenance, or storage.
The positive nitrogen pressure prevents oxygen and moisture from entering the system, which causes corrosion and contamination. When the equipment is ready for commissioning or return to service, the nitrogen is pumped out.
What Is Nitrogen Purging?
Nitrogen purging (also known as nitrogen drying) is a maintenance technique that flushes out oxygen, moisture and remnant hydrocarbons from industrial and energy systems. Nitrogen gas is inert, making it safe to inject into petrochemical systems containing combustible material.
This process enhances safety during plant maintenance. Onshore and offshore maintenance services in particular are at risk of potential combustion scenarios if the equipment is not sufficiently purged before maintenance.
Applications of Nitrogen Purging and Preservation
Our nitrogen purging and preservation services support a wide range of industrial and energy systems, including:
- Oil, natural gas, and petrochemical processing plants and refineries
- Process pipelines and flowlines
- Rotating and static equipment
- Pressure vessels, tanks, and separators
- Offshore platforms and floating product storage and offloading vessels.
- Oil and gas systems or equipment in long-term storage or awaiting commissioning.
High-Capacity Nitrogen Mobilisation
MCCS mobilises all essential equipment to your facility for:
- Removal of hydrocarbons before maintenance, shutdown, or turnaround activities
- Elimination of oxygen and moisture before preparing systems for start-up or introduction of hydrocarbons
- Preservation of systems and equipment following hydrotesting, placement into long-term storage, or construction project delays.
Full Certification & Handover
Upon completion of nitrogen drying and preservation services, MCCS issues, where applicable:
- Inerting certificate
- Oxygen level report
- Hydrocarbon-free certificate
- Test data and monitoring logs
- As-built purging diagrams
All documentation is compiled and handed over to operations, commissioning, or maintenance teams for formal system acceptance.
Engineering, Planning & Method Statement Preparation
Each nitrogen purging operation begins with comprehensive engineering and technical planning, including:
- Detailed study of P&IDs, isometrics, and line diagrams
- Hazard identification and risk assessment (HIRA)
- Identification of purge points, vent points, and isolation boundaries
- Selection of purge methodology
- Flowrate modelling and nitrogen volume calculations
- Pressure control strategy development
- PTW, LOTO, and full safety-compliance planning
Our engineered approach ensures an optimised and efficient operation tailored to the unique conditions of your facility.
Nitrogen Purging Methods
MCCS selects the most effective nitrogen purging technique based on system size, geometry, and contaminant profile.
Flow Displacement Purging
The nitrogen displaces contaminants using laminar flow. Ideal for large vessels and pipelines.
Dilution Purging
The nitrogen is mixed with the existing gas stream, reducing oxygen and/or hydrocarbon contamination to a safe level. This method is typically applied when flow displacement is not suitable.
Pressure-Vacuum Cycles
Used for reactors and tanks that require controlled pressurisation, this technique introduces nitrogen gas at high pressure before a vacuum is created to purge contaminants
On-Site Setup & System Isolation
Before nitrogen drying begins, we ensure the system is stable, properly isolated, and ready for inerting operations through:
- Verification of blinds, spades, or double-block-and-bleed valves
- Pressure release and line depressurisation
- Testing of vent points and drain points
- Installation of temporary hoses, manifolds, and monitoring systems
- Establishment of safe working zones and exclusion areas
Controlled Nitrogen Injection
Our technicians ensure the precisely-controlled introduction of nitrogen and consistent performance through:
- Gradual system pressurisation
- Continuous flow regulation
- Temperature-controlled injection (including hot N₂ when required)
- Real-time oxygen and gas monitoring
- Maintaining safe pressure limits throughout the purge
Oxygen & Gas Level Monitoring
As the nitrogen purge progresses, we utilise calibrated analysers to continuously monitor:
- Oxygen concentration
- Hydrocarbon presence
- H₂S or flammable vapours
- Dew point and moisture content (when required)
The procedure continues until certified safe limits are achieved (typically <1% O₂, or as specified by the client).
Why Choose MCCS for Oil and Gas Services
MCCS delivers safe, efficient, and cost-effective nitrogen drying and preservation solutions. Our trained and certified team conduct thorough on-site assessments, nitrogen requirement calculations, and provides you with solutions that fit your schedule and budget.
Our international onshore and offshore services are compliant with international standards. Ensuring smooth, safe, and efficient project performance.
For project inquiries or onshore and offshore maintenance support, reach out to our team today.
MCCS has had the privilege of serving a diverse portfolio of international clients
