EN ISO 14175:2008 PDF

Overview

EN ISO 14175:2008 - "Welding consumables - Gases and gas mixtures for fusion welding and allied processes" is a CEN-endorsed adoption of ISO 14175:2008. It provides a standardized classification and designation system for shielding, backing, process and assist gases used in fusion welding and related processes (tungsten arc welding, gas‑shielded metal arc welding, plasma and laser welding/cutting, arc braze welding, etc.). The standard helps users select the correct shielding gases and simplifies qualification by defining chemical composition, naming conventions, purity and mixing tolerances.

Key topics and technical requirements

• Scope: Covers gases/gas mixtures used in fusion welding and allied processes (process numbers per ISO 4063). Fuel gases (acetylene, propane, natural gas) and resonator gases for lasers are excluded.
• Classification system: Gases are classified by main group and sub‑group (e.g., I, M1–M3, C, R, N, O, Z) based on chemical properties and metallurgical behaviour. Table 2 in the standard sets composition ranges for each class.
• Designation rules: Formal designation includes the ISO number, class symbol and component symbols with nominal volume percentages (e.g., ISO 14175 – M25 – ArCO – 6/4 for Ar + 6% CO + 4% O2).
• Component symbols: Standard chemical symbols used include Ar, CO, O, He, H, N (base gas followed by other components in descending percent).
• Mixture tolerances: Specified as delivered by the supplier. Key tolerances (Table 3):

  • 5% nominal concentration: ±10% of nominal

  • 1–5% nominal: ±0.5% absolute