CLASSIFICATION OF SHIELDING GASES (ISO 14175:2008)

1 Rev. 2017-11-02 CLASSIFICATION OF SHIELDING GASES (ISO 14175:2008) Short term Components in nominal percentage of volume [%] Main group Sub group Oxidizing Inert Reducing Low reactivity CO2 O2 Ar He H2 N2 I 1 100 2 100 3 Balance 0,5 He 95 M1 1 0,5 CO2 5 Balance a 0,5 H2 5 2 0,5 CO2 5 Balance a 3 0,5 O2 3 Balance a 4 0,5 CO2 5 0,5 O2 3 Balance a M2 0 5 < CO2 15 Balance a 1 15 < CO2 25 Balance a 2 3 < O2 10 Balance a 3 0,5 CO2 5 3 < O2 10 Balance a 4 5 < CO2 15 0,5 O2 3 Balance a 5 5 < CO2 15 3 < O2 10 Balance a 6 15 < CO2 25 0,5 O2 3 Balance a 7 15 < CO2 25 3 < O2 10 Balance a M3 1 25 < CO2 50 Balance a 2 10 < O2 15 Balance a 3 25 < CO2 50 2 < O2 10 Balance a 4 5 < CO2 25 10 < O2 15 Balance a 5 25 < CO2 50 10 < O2 15 Balance a C 1 100 2 rest 0,5 O2 30 R 1 Balance a 0,5 H2 15 2 Balance a 15 < H2 50 N 1 100 2 Balance a 0,5 N2 5 3 Balance a 5 < N2 50 4 Balance a 0,5 H2 10 0,5 N2 5 5 0,5 H2 50 Balance O 1 100 Z Gas mixtures with components, which are not listed in the table or gas mixtures with a of the specified range.

2 B a For this CLASSIFICATION Argon may be replaced partially or completely with helium. b Two gas mixtures with the same Z- CLASSIFICATION must not be replaced against each other. Rev. 2017-11-02 EXAMPLE For gas mixtures containing CLASSIFICATION ISO 14175 Designation 6% carbon dioxide, 4% oxygen in argon M25 ISO 14175 M25 ArCO 6/4 30% helium in argon I3 ISO 14175 I3 ArHe 30 5% hydrogen in argon R1 ISO 14175 R1 ArH 5 7,5% argon, 2,5% carbon dioxide in helium M12 ISO 14175 M12 HeArC 7,5/2,5 0,05% oxygen in argon Z ISO 14175 Z ArO 0,05 0,05% xenon (Xe), in argon Z ISO 14175 Z Ar+Xe 0,05 TOLERANCES OF MIXTURES Component gas nominal concentration [%] Allowed tolerances > 5 10 % of the nominal 1 to 5 0,5 % absolute < 1 Not specified in ISO 14175 EXAMPLE An addition of 25 % CO2 nominal value shall not vary more than 2,5 % (from 22,5 % to 27,5 %) An addition of 2,5 % oxygen shall not vary more than 0,5 % (from 2,0 % to 3,0 %) PURITIES AND DEW POINT Main groups/gas Purity % by volume minimum Dew point at 0,101 MPa C Moisture ppm max.

3 Volume I inert 99,99 -50 40 M1 a gas mix 99,9 -50 40 M2 a gas mix 99,9 -44 80 M3 a gas mix 99,9 -40 120 C a carbon dioxide 99,8 -40 120 R reducing 99,95 -50 40 N nitrogen 99,9 -50 40 O oxygen 99,5 -50 40 NOTE For certain applications a higher purity and/or lower dew point may be recommended to avoid possible oxidation and contamination a Nitrogen: 1 000 ppm maximum