Closed Loop Sample Handling System (CLSS): Engineering Safety, Precision, and Efficiency in Process Gas Sampling

Whitepaper
|
20.04.2026
|
Axis Solutions Limited
about

In today’s process-driven world, quality assurance is the heartbeat of process, and Gas Sampling technique is the key requirement. Yet, a traditional manual sampling system is used where operators are exposed to hazardous fluids, compromise sample integrity, and contribute to fugitive emissions — posing both safety and environmental threats.

Axis Solutions Limited, a leader in analytical and automation systems, addresses this challenge through its Closed Loop Sample Handling System package (CLSS) – an engineered, modular, and safety-certified solution designed to collect representative process samples without atmospheric exposure.

With increasing regulatory demands such as OSHA, PESO, and ISO 45001, Axis CLSS offers zero-leak, zero-contact, and zero-emission sampling – ensuring operator safety, process accuracy, and environmental compliance.

Why CLSS? The Industrial Imperative

Sampling in chemical, refinery, fertilizer, and power sectors is essential but risky. Operators frequently handle high-pressure or toxic media such as H₂S, hydrocarbons, amines, or acids, where even minor leaks can be catastrophic.

Challenges with Conventional Sampling:

  • Operator Exposure: Contact with hazardous media during venting or connection.
  • Sample Contamination: Exposure to atmosphere alters sample composition.
  • Fugitive Emissions: Each open sampling event releases VOCs and process gases.
  • Downtime & Waste: Manual venting causes product losses and unsafe delays.

The Closed Loop Advantage:

Axis CLSS enables sampling under process pressure in a completely sealed system. The system captures the sample, isolates it safely, and optionally returns residual media to the process — ensuring:

  • No operator contact
  • No emissions
  • No sample contamination
  • No production interruption
  • No interruption on sampling or measuring. 

Key Result: Closed Loop Sampling reduces fugitive emissions by up to 95%, improves sample reliability by 40%, and enhances operator safety metrics by over 70% (industry benchmark, API RP 555).

Why Axis CLSS

Axis Solutions Limited brings over 25 years of engineering excellence and is recognized as one of India’s leading innovators in analytical and automation solutions.

Axis CLSS Highlights:

  • NACE-certified materials for corrosion resistance.
  • TPED & DOT-compliant sample cylinders on request.
  • Quick-disconnect self-sealing fittings withstand internal pressure.
  • Bypass and depressurization circuits built-in.
  • Compact, modular design requiring minimal operator time or training.
  • Customizable end connections — flanged, threaded, or bespoke.
  • Integration-ready with on-line analyzers and field calibration systems.

Global Adoption:
Closed-loop sampling systems were pioneered by process safety leaders in Europe and North America. In India, adoption began with refineries and fertilizer plants (IOCL, BPCL, IFFCO, and GNFC, ONGC), where Axis has played a key role as a system integrator and package manufacturer.

Yet, awareness remains a grey area – many plants continue using traditional sampling techniques due to legacy inertia, cost misconceptions, and lack of training. Axis CLSS bridges this gap with affordable, customizable, and easy-to-operate systems delivering global safety performance at Indian cost economics.

Technical Overview and Key Components

System Architecture:
The Axis CLSS is designed for safe extraction, sealing, and return under full process conditions.

Process Flow:
1. Collection: Sample drawn into sealed cylinder under process pressure.
2. Sealing & Disconnection: Self-sealing quick connects allow safe removal.
3. Depressurization: Residual pressure vented to process, not atmosphere.
4. Return to Process (optional): Remaining media routed back to main line.

Key Components:

  • Quick-Disconnect Couplings: Rapid, leak-free attachment/detachment, pressure-rated.
  • Cylinder Valves: Control flow, isolation, and depressurization.
  • Sample Cylinder / Bottle: Designed for high-pressure containment.
  • Flexible Tubing: Ensures vibration absorption and secure mounting.
  • Bypass & Vent Lines: Maintain process flow during sampling.
  • Support & Labeling: Indicates MAWP, temperature, and safety data.

Material & Design Features:

  • NACE-certified SS316/Alloy C components for aggressive chemicals.
  • Working Pressure: Up to 250 bar.
  • Temperature Range: 20°C to +250°C.
  • Leak Integrity: <10⁻⁶ cc/sec (He).
  • Certifications: TPED/DOT optional for export and transport cylinders.

Advantages and Benefits

Operational & Safety Benefits:

  • Zero operator exposure.
  • Safe depressurization.
  • Leak-free sampling under process pressure.

Technical & Quality Benefits:

  • True process representation.
  • Reduced analyzer recalibration.
  • Extended analyzer lifespan.

Economic & Sustainability Benefits:

  • Lower O&M costs.
  • Reduced insurance premiums.
  • VOC emission reduction supporting ESG goals.

Industry Applications

  • Sector: Petroleum Refining, – Typical Media: Naphtha, Gas Oil – Purpose: Quality control & blending
  • Sector: – Chemical Processing, – Typical Media: Acids, solvents, amines – Purpose: Quality control Product consistency verification
  • Sector: – Petroleum Refining – Condensate, boiler feed – Purpose: Purity and corrosion monitoring
  • Sector: – Fertilizer, Typical Media – Ammonia, CO₂, methanol – Purpose: Process optimization

The Axis Advantage

  • End-to-End Capability: In-house design, fabrication, testing, and validation.
  • Compliance Ready: PESO, IECEx, ATEX zones compatible.
  • Legacy Upgrade: Retrofit-ready for existing open sampling systems.
  • Digital Integration: Compatible with Axis analytical panels and automation platforms.

Axis CLSS is not just a product – it’s a process reliability enabler, engineered for global performance with local support.

Conclusion

The need for safe, compliant, and sustainable sampling has never been greater. Closed Loop Sampling is transforming global chemical industries — from manual to intelligent, hazardous to safe, and reactive to proactive operations.

Yet in India, this remains a grey zone, with many plants unaware of its measurable economic and safety ROI. Axis Solutions Limited bridges this gap by offering a proven, field-tested CLSS that combines engineering depth, affordability, and adaptability.

Axis CLSS — Redefining Sampling Safety and Efficiency.
Safer Operators. Smarter Plants. Sustainable Future.

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