Case study · HPHT Reactors & Cells

50 mL Titanium HPHT Cell for Stirred Fluid Studies at 500 bar with Full Visibility

For a public research center in materials chemistry, IRIAN Mecatronics designed and built a 50 mL HPHT cell. This custom equipment allows for the study of fluid phase behavior under 500 bar and 150°C, with full visual observation and stirring in a chemically inert environment (CO2).

Client: Public research center in materials chemistry
Field: Materials Chemistry
Technique: Phase Behavior, Visualization Under Pressure

01 — The research question

How to characterize a fluid under high pressure in a minimal reactive volume, with both stirring and direct observation?

Studying the phase behavior of fluids (liquids, gases, CO2) under extreme conditions often requires combining several functionalities in a single piece of equipment: maintaining stable pressure and temperature, ensuring sample homogeneity, observing phenomena in real time, and guaranteeing perfect chemical inertness. The difficulty increases when the available sample volume is very small, which concentrates mechanical and thermal stresses in a confined space.

In this project, a laboratory needed to conduct these studies on 50 mL volumes at 500 bar and 150°C, with full CO2 compatibility. Standard lab reactors or PVT cells do not combine all these requirements: a titanium body, very low volume, internal stirring, a viewing window covering the entire volume, and features for easy, frequent maintenance. Off-the-shelf solutions are either too specialized (a PVT cell without stirring, a stirred reactor without full visibility) or made of unsuitable materials (stainless steel).

To integrate a magnetic stirrer, a full-view window, and multiple connections into a titanium body of only 50 mL capable of withstanding 500 bar, without compromising the reliability of critical seals or the ease of maintenance.

02 — Our approach

A design guided by reliability and serviceability

The cell's design is based on three technical choices that directly address the failure points of standard equipment under these intensive operating conditions.

Securing pressurization and volume control

To ensure stable pressure over long periods and make the test fail-safe in case of a power outage, we selected a non-reversible mechanical power transmission. Unlike a direct drive, this system locks in position when motor torque is absent. The pressure is maintained passively, safeguarding the experiment without relying on an active safety brake.
Simplifying maintenance by separating functions

Disassembling a sapphire window for cleaning is a high-risk operation for the HP seal. We designed a double-flange assembly: the first, external flange secures and seals the sapphire and is never touched during routine operations. The second allows access to the cell for cleaning. The risk of damaging the critical seal is thereby eliminated.
Ensuring leak-tightness with a contactless drive

Introducing a stirrer into a 500 bar vessel creates a potential leak path. To prevent this, torque is transmitted via magnetic coupling through a titanium diaphragm. This principle eliminates any mechanical shaft pass-through and any dynamic rotating seal, ensuring absolute leak-tightness and maximum reliability, even with corrosive fluids like CO2.

03 — The outcome

What this equipment made possible

[TO BE COMPLETED]

Does your project have similar requirements?

Pharmaceuticals / API Synthesis

Common constraint: Reactions in supercritical media (CO2) in small reactors, requiring observation, stirring, and chemical inertness. What would remain the same: The variable-volume HP cell principle, the seal-less magnetic stirrer, visualization under pressure, and CO2 compatibility.

Geosciences / Reservoir Fluid Studies

Common constraint: Analyzing the phase behavior (PVT) of hydrocarbons or CO2 sequestration fluids under downhole conditions. What would remain the same: The HPHT cell, precise volume/pressure control, visualization, and stirring. A related piece of equipment is our Multi-Mode HPHT Reactor for Corrosive Geoscience Research.

Energy / Hydrogen Storage

Common constraint: Measuring the absorption/desorption of hydrogen by materials as a function of pressure and temperature. What would remain the same: The variable-volume cell principle for precise gas quantity control, temperature regulation, and intrinsic safety.

04 — Specifications

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

Show specifications · 500 bar [7,250 psi] · 50 mL · 3 °C to 150 °C [37 °F to 302 °F]

Technical specifications — 50 mL Titanium HPHT Cell for Stirred Fluid Studies at 500 bar with Full Visibility
Maximum operating pressure	500 bar [7,250 psi]
Maximum volume	50 mL
Operating temperature range	3 °C to 150 °C [37 °F to 302 °F]
Wetted materials	Titanium Ti-6Al-4V ELI (Grade 23), FFKM, PEEK, PTFE
Stirring speed range	50 to 1000 rpm
Flow rate range (volume variation)	1 µL/min to 20 mL/min
Fluid connections	4 x 1/16" Valco type fittings

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 titanium cell be adapted for higher pressures and temperatures, like 1000 bar and 300°C?

Yes, the design principle can be adapted to more severe conditions. Reaching 1000 bar and 300°C would require a complete resizing of the cell body and flanges, as well as the selection of appropriate materials and seals (e.g., nickel alloys and metal seals). The key principles, such as magnetic stirring and fail-safe pressurization, would remain valid.

How would you modify this reactor to handle highly corrosive fluids like H2S?

The main adaptation would be to change the material of construction. The titanium would be replaced by a nickel alloy such as Hastelloy C-276 or Inconel, known for their excellent resistance to acid corrosion (H2S). The design would remain very similar, as the sealing principles (magnetic drive, double-flange window) are material-independent and particularly well-suited for hazardous fluids.

Is it possible to build a similar cell with a larger volume, for instance, 1 liter?

Yes, our reactors and cells are always custom-designed. Increasing the volume to 1 liter is entirely feasible. This would involve resizing all pressure-containing parts and the magnetic stirrer to ensure effective homogenization. However, the principle of full visibility would become more complex and costly to implement on a large, high-pressure volume.

Can a version of this equipment be ATEX-certified for use in explosive atmospheres?

Yes, all our equipment can be designed for ATEX compliance. This involves integrating certified components (motors, sensors, instrumentation) and following specific design rules to prevent any hot spots or ignition sources. The entire system, including the control cabinet, would then be designed and certified for the specified working environment, as on our flammable gas autoclave bench.

Is your current equipment limiting your test conditions in pressure, temperature, or chemical compatibility?

Describe your challenge to us, even if it seems non-standard. Our engineering team will analyze the feasibility of your project and get back to you with a technical proposal.

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