Arc welding equipment - Gas consoles for welding and plasma cutting systems
1Key Takeaways
What is IEC 60974 ‑ 8 about? IEC 60974 ‑ 8 is one of the parts of a multi-series standard. IEC 60974-8 specifies safety and performance requirements for gas consoles intended to be used with combustible gases or oxygen. These gas consoles are designed to supply gases for use in ar…
2Expert Interpretation
In-depth analysis of BS EN IEC 60974-8:2021 on the safety requirements for gas control consoles for welding and plasma cutting systems, covering key technical specifications such as electrical protection, mechanical design, gas pipelines, etc., providing implementation suggestions and comparative analysis of the new and old versions.
Analysis of the core content of the standard
BS EN IEC 60974-8:2021, as Part 8 of the IEC 60974 series of standards, specifically specifies the safety requirements for gas consoles used in welding and plasma cutting systems. This standard replaces the 2009 edition. The main technical changes include:
Key safety requirements
| Technical dimensions | Requirements of the 2009 edition | New content of the 2021 edition |
|---|---|---|
| Electrical protection | IP21 protection level | It is clarified that the micro-environment pollution level must reach Level 2 or above (achieved by coating/potting) |
| Explosion-proof design | General requirements | Four new specific explosion-proof schemes (purification type/safety design/open/solid structure) |
| Temperature control | General temperature rise limit | The surface temperature is required to be at least 20% lower than the ignition point of the combustible gas |
Key points for technical implementation
Safety design of gas pipelines
Chapter 10 of the standard clearly requires:
- The color coding specified in ISO 3821 shall be adopted (combustible gas-red, oxygen-blue)
- Pipeline joints shall be designed as non-interchangeable structures
- The leakage test pressure is 125% of the rated value, and the leakage volume is ≤5 sccm
Typical application scenarios
In the plasma cutting system, the external gas console must independently meet the following requirements:
- Physical isolation from the power supply (Clause 9.6)
- Rated parameter identification (Clause 12.1 requires the maximum intake pressure, gas type, etc. to be marked)
- Automatic purge function (Clause 9.3 requires that the concentration of flammable gas after ventilation is lower than the lower explosion limit)
Compliance recommendations
Design phase
It is recommended to adopt a three-stage verification method:
- Identify single point failure risks through FMEA analysis (Clause 9.2)
- Use infrared thermal imager to verify the temperature margin of high-temperature components (Clause 7.3)
- Perform explosion simulation tests (Clause 9.4.3.2)
Document requirements
According to Clause 13.2, the technical documentation must include:
- Gas purity requirements
- Pipeline purge operation procedures
- Combustible gas hose replacement cycle
- Flashback arrester installation instructions