Case study · Extreme environment simulation systems

Safe HPHT materials testing in flammable gas: a custom ATEX multi-autoclave rig

IRIAN Mecatronics designed and built a custom test rig for an R&D center studying materials aging under extreme conditions. The equipment safely exposes samples to reactive gases like hydrogen at high pressure and high temperature within an ATEX-certified environment.

Client: R&D Center
Field: Materials science, energy
Technique: Aging tests, Materials compatibility, ATEX environment testing

Extreme environment simulation systemsConfidential project · photo withheld

01 — The research question

How can we safely test materials in a flammable HPHT environment?

Testing materials in a controlled environment that combines high pressure, high temperature, and a flammable gas is a major challenge. Ensuring absolute safety for operators and the facility imposes design constraints that go far beyond standard laboratory equipment.

For this project, an R&D center needed to expose materials to hydrogen at high pressure and temperature. Off-the-shelf autoclaves are not designed to handle these three constraints (HP, HT, flammable gas) simultaneously. This required a custom design and certification compliant with the ATEX directive, integrating risk management that only custom equipment can provide from the ground up.

The key challenge was to achieve high experimental performance—including rapid pressure and temperature ramps—while completely mitigating the explosion risk associated with handling flammable gases that have low ignition thresholds.

02 — Our approach

Our approach: A design centered on risk management

Our engineering team analyzed the risks at every stage of the process to design a system where safety is not an option, but the guiding principle. Every choice, from the vessel material to the handling ergonomics, stems from this requirement.

Managing explosion risk with multi-layered safety

Since the pressurized gas is flammable, any leak could create an explosive atmosphere. We combined prevention (ATEX-certified components), containment (zone separation), and an active response (leak detection and automatic safety shutdown). This allows the operator to launch tests with confidence, as the system autonomously manages any anomalies.
Selecting a material resistant to embrittlement

At high pressure and temperature, hydrogen can embrittle standard steels like 316L stainless steel, leading to failure. Our approach was to select a material grade inherently resistant to this phenomenon, ruling out standard solutions. This ensures the long-term longevity and integrity of the high-pressure autoclave over its entire service life.
Simplifying handling for rapid test cycles

HPHT autoclave lids are heavy, and opening and closing them frequently is a source of risk and wasted time. We designed an assistance system that eliminates operator strain and avoids disconnecting rigid piping. Sample changes are faster, simpler, and safer.

03 — Beyond this project

Does your project look like this case?

Energy production (e-fuels, hydrogen, ammonia)

For testing the durability of catalysts or reactor materials in the presence of reactive HPHT fluids, the multi-level safety approach (ATEX, detection), compatible material selection, and independent control of multiple custom reactors would remain identical.

Pharmaceutical industry

For synthesis reactions like hydrogenation under pressure with flammable reagents, the ATEX risk management, precise temperature control, and loading ergonomics are directly transferable. Materials (e.g., Hastelloy) and cleanability requirements would be adapted.

Aerospace

For qualifying the compatibility of components with propellants like hydrogen, the integrated safety approach and critical material selection are essential. The main adaptations would involve managing cryogenics or faster thermal cycles.

04 — Specifications

The values for this project. Every system is custom-built, so they adapt to your requirements.

Show specifications · Reactive or flammable gas (e.g., hydrogen) under high pressure and high temperature · Designed for use in potentially explosive atmospheres (ATEX) · Independent pressure and temperature control of multiple autoclaves on a single test bench

Technical specifications — Safe HPHT materials testing in flammable gas: a custom ATEX multi-autoclave rig
Test environment	Reactive or flammable gas (e.g., hydrogen) under high pressure and high temperature
Safety	Designed for use in potentially explosive atmospheres (ATEX)
Process control	Independent pressure and temperature control of multiple autoclaves on a single test bench
Dynamics	Rapid temperature and pressure ramps
Safety function	Automatic vacuum and purge sequences

IRIAN Mecatronics designs and builds custom high-pressure, high-temperature equipment for research laboratories, technical centres and industry.

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05 — FAQ

Frequently asked questions

Can this type of ATEX test rig be used with flammable gases other than hydrogen, such as methane or ammonia?

Yes, the design principle can be adapted to other flammable gases. The first step for our engineering team is to analyze the gas properties (flammability, corrosivity, material compatibility) to adjust the selection of materials, seals, and sensors. The three-tiered safety approach (prevention, containment, detection) remains the foundation, but detection thresholds and purge scenarios would be reconfigured.

Is it possible to design a system with a single autoclave, or conversely, with a larger number of reactors?

Absolutely. The system shown is a dual-autoclave bench, but it is fully modular. We can design a single-autoclave version for more targeted research needs, or a bench with multiple reactors, each controlled independently. The control and instrumentation architecture is designed to be scalable, ensuring the same rigorous safety and control regardless of the number of reactors.

How are the maximum pressure and temperature ranges for these aging autoclaves determined?

The pressure and temperature ranges are custom-defined based on your experimental needs. They are the starting point for the mechanical design, in accordance with the Pressure Equipment Directive (PED). The choice of materials, wall thickness, closure type, and heating technology are directly dictated by these operating conditions to ensure safety and performance.

What is the level of automation and data traceability for such a test rig?

The level of automation is defined with you. Our systems typically include full control via a PC interface, allowing users to program pressure and temperature cycles, manage safety sequences (purge, emergency shutdown), and continuously record all process parameters. This traceability is essential for analyzing test results and validating experimental protocols.

Does your process involve flammable fluids under high pressure, and are you looking for a testing solution that guarantees your team's safety?

Describe your constraints and the operating conditions you need to achieve. Our engineering team will analyze your project's feasibility and get back to you with a detailed technical proposal.

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