In scientific research and industrial production, the measurement and control of flammable and explosive gases such as hydrogen and acetylene not only demand high stability and accuracy from instrumentation but also impose stringent safety requirements on the associated devices. Particularly in hazardous areas where explosive gases are present, achieving high‑precision, automated flow measurement and control while ensuring safe equipment operation has become a critical challenge for systematic domestic substitution.

Intrinsically Safe Principles and Explosion-Proof Rating Explained:

Intrinsic Safety (Intrinsic Safety, abbreviated as Ex i) It is a type of electrical explosion-proof protection. Its basic principle is to limit the voltage, current, and stored electrical energy (such as energy stored in inductors and capacitors) within the circuit, ensuring that under specified normal operating conditions and fault conditions, any electrical sparks or thermal effects generated are insufficient to ignite the surrounding explosive gas atmosphere.

Basis: IEC 60079-11:2023 Explosive Atmospheres Part 11 Part: Intrinsically safe type “ i “Protected devices”

Take Ex ia IIC T6 Ga as an example:

Common misconception: Treating T6 as indicating “stronger explosion protection.” T6 signifies stricter surface temperature limits and does not imply a more robust explosion-proof protection type. The actual equipment selection must be determined comprehensively, taking into account the hazardous area classification, gas group, and certification requirements.

▲ACU20FD-MC Intrinsically Safe Gas Mass Flow Controller (IP65)

To meet the demands of complex industrial environments involving hazardous or explosive gases, ACCU’s self-developed ACU20FD series intrinsically safe gas mass flow controllers and meters combine high precision with intrinsic safety. Designed specifically for gas measurement and control in hazardous industrial settings, they ensure safety while delivering accurate measurements and reliable operational stability.

The ACU20FD series intrinsically safe gas mass flow controllers employ thermal mass flow measurement technology, with typical ranges spanning 0 to (2 SCCM...300 SLM). Measurement accuracy reaches up to ±0.5% F.S., and repeatability is ±0.2% F.S. Featuring short warm-up times, minimal zero-point drift, and stable response, they are particularly well suited for precise control in continuous process applications.

• Explosion-proof rating: Ex ia IIC T6 Ga.

• Suitable for measuring and controlling the flow of hazardous gases.

• High-precision measurement: It comes with built-in calibration parameters for multiple gases and supports the measurement and control of common flammable and explosive gases, including O₂, H₂, and certain natural gas components. For specific gas mixtures, calibration or parameter configuration can be performed based on the actual gas composition to meet measurement requirements under various process conditions. The exact types of gases supported and the measurement ranges for gas mixtures are subject to the model configuration.

• Pressure and Corrosion Resistance: It exhibits excellent pressure resistance, with a maximum rating of 40 MPa (and can operate under vacuum conditions; specific vacuum‑compatible ranges and performance specifications are subject to the technical data for the respective model). The body is constructed from stainless steel, providing high mechanical strength and superior corrosion resistance. For corrosive media such as Cl⁻ and H₂S, materials can be selected to match the specific composition, concentration, temperature, and pressure conditions. Seals are available in perfluoroelastomer (FFKM), fluoroelastomer (Vilton), nitrile rubber (NBR), or ethylene propylene diene monomer (EPDM), ensuring low leakage rates and safe operation with a wide range of gases.

• Multifunction Communication: In addition to standard analog inputs and outputs, it supports RS485/RS232 communication interfaces and the Modbus RTU protocol, facilitating integration with automation control systems.

• Flexible configuration: Offers threaded, ferrule, and flanged process connections to meet the requirements of various process piping systems.

▲ACU20FD-MM Thermal Gas Intrinsically Safe Mass Flow Meter (Intrinsically Safe Explosion-Proof, IP65)

Omni‑scenario compatibility: addressing core needs across multiple industries

ACU20FD Series Widely used in Fields include petrochemicals, natural gas transmission, hydrogen energy, supply of process gases for semiconductors, CVD deposition, plasma etching, vacuum processes, and analytical instrumentation. It is suitable for the measurement and control of flow rates of combustible gases (such as hydrogen and acetylene) and other process gases. , providing reliable support for continuous production and automated management in hazardous environments.

Safety is the prerequisite for industrial measurement, and precision is at the heart of process control. ACCU We remain focused on high-precision mass flow measurement and control technologies, offering intrinsically safe, flexibly configurable, and reliably stable products to deliver more specialized gas flow solutions for hazardous industrial environments.

For precise selection based on operating conditions and detailed product specifications and integration solutions, please contact us to receive a customized selection guide and tailor an efficient flow measurement and control solution for your production line.