The most typical cylinder outlet connections used with the most common gases, pure gases and mixtures.

These tables identify the most typical cylinder outlet connections used with the main gases and mixtures. The referenced standards are sometimes implemented with slight variations in the countries where the standard applies, e.g. DIN in Europe. If necessary, the cylinder outlet itself must be confirmed with your local supplier at the time of delivery.

AFNOR (Association Française de Normalisation)

Connector type	Connector description	Generic gas property	Example gases or mixtures components
NF B	W 30 x 1.75	Oxidiser	Industrial Air
NF C	SI 21.7 x 1.814	Inert Gases	Argon, Helium, Nitrogen
NF E	SI 21.7 x 1.814 LH	Flammable	Hydrogen, Hydrogen Mix >4%
NF F	SI 22.94 x 1.814 INT	Oxidiser	Oxygen
NF G	SI 26 x 1.5 INT	Oxidiser	Nitrous Oxide
NF H	W 22.91 x 1.814 LH INT	Flammable	Acetylene
NF J	W 25.4 x 3.175	Corrosive	Chlorine
NF K	W 27 x 2	Corrosive	Hydrogen Chloride
NF L	W 27 x 2	Oxidiser	Inert gases + Oxygen Mix > 21%
NF M	W 30 x 2	Oxidiser	Inert gases + Oxygen Mix > 21% & CO2 < 7%
NF P	W 27 x 2	Oxidiser or corrosive	Nitric Oxide, Nitrogen Dioxide

BS 341 (British Standard)

Connector type	Connector description	Generic gas property	Example gases or mixtures components
BS 341 No. 2	G 5/8" LH	Flammable	Acetylene
BS 341 No. 3	G 5/8" INT	Inert	Air, Argon, Neon, Nitrogen
BS 341 No. 3	G 5/8" INT	Oxidiser	Oxygen
BS 341 No. 4	G 5/8" LH INT	Flammable	Acetylene, Hydrogen
BS 341 No. 4	G 5/8" LH INT	Flammable	Carbon Monoxide, Methane, Natural Gas
BS 341 No. 6	G 5/8"	Toxic	Chlorine, Hydrogen Chloride
BS 341 No. 7	G 5/8" LH	Flammable Refrigerants	Flammable Refrigerants
BS 341 No. 8	W 0.860" x 14 TPI	Non Flammable	Carbon Dioxide
BS 341 No. 10	G 1/2"	Toxic	Ammonia
BS 341 No. 12	G 1/2"	Toxic	Sulphur Dioxide
BS 341 No. 13	W 11/16" - 20 TPI	Oxidiser	Nitrous Oxide
BS 341 No. 14	G 3/8"	Toxic	Hydrogen Cyanide, Nitric Oxide
BS 341 No. 15	G 3/8" LH	Toxic	Carbonyl Sulphide, Hydrogen Sulphide

DIN 477 (Deutsche Industrie Norm)

Connector type	Connector description	Generic gas property	Example gases or mixtures components
DIN 477 No. 1	W 21.8 x 1/14" LH	Flammable	Hydrogen, Propane
DIN 477 No. 2	W 21.8" x 1/14" LH	Flammable	Propane
DIN 477 No. 3	Yoke	Flammable	Acetylene
DIN 477 No. 3.1	M 24 x 2" LH	Flammable	Acetylene
DIN 477 No. 5	W 1" x 1/8" LH	Toxic	Carbon Monoxide
DIN 477 No. 6	W 21.8 x 1/14"	Various	Argon, Helium, Carbon Dioxide
DIN 477 No. 7	G 5/8"	Toxic	Sulphur Dioxide
DIN 477 No. 8	W 1" x 1/8"	Toxic	Boron Trichloride
DIN 477 No. 9	G 3/4"	Oxidiser	Oxygen
DIN 477 No. 10	W 24.32 x 1/14" RH	Inerts	Nitrogen
DIN 477 No. 11	G 3/8"	Oxidiser	Nitrous Oxide (>3 l size)
DIN 477 No. 12	G 3/4" INT	Oxidiser	Nitrous Oxide (<3 l size)
DIN 477 No. 13	G 5/8" INT	Non Flammable	Air
DIN 477 No. 14	M 19 x 1.5 LH	Various	Mixtures

ISO 5145 (Provisional standard, previously NEVOC)

Connector type	Connector description	Generic gas property	Example gases & mixtures components
ISO 5145 No.1	W 24 x 2 11,2 - 16,8 RH	Inert	Medical Helium & Xenon
ISO 5145 No.2	W 24 x 2 11,9 - 16,1 RH	Oxidiser	Oxygen
ISO 5145 No.4	W 24 x 2 13,3 - 14,7 RH	Inert	Inert gases & mixes, except He & Xe
ISO 5145 No.9	W 24 x 2 13,3 - 14,7 LH	Flammable	Mixes with a flammable gas, except Hydrogen
ISO 5145 No.10	W 24 x 2 14 - 14 LH	Flammable	Hydrogen
ISO 5145 No.11	W 27 x 2 11,8 - 20,2 RH	Inert	Nitrogen
ISO 5145 No.17	W 27 x 2 16 - 16 RH	Inert	Carbon Dioxide
ISO 5145 No.24	W 27 x 2 16 - 16 LH	Flammable	LPG
ISO 5145 No.30	W 30 x 2 15,9 - 20,1 RH	Inert	Helium, Argon, Nitrogen, inert mixes*
ISO 5145 No.32	W 30 x 2 17,3 - 18,7 RH	Oxidiser	Oxygen*
ISO 5145 No.38	W 30 x 2 15,2 - 20,8 LH	Flammable	Mixes with a flammable gas*
ISO 5145 No.41	W 30 x 2 17,3 - 18,7 LH	Refrigerants	Refrigerant gases**

* Working pressure above 250 bar in Europe and 182 bar in USA
** Flammable according to ISO 5145, for inert No. 4 can be used when FTSC codes fit with the mixture

NEN 3268 (Nederlandse Norm)

Connector type	Connector description	Generic gas property	Example gases or mixtures components
LU 0	M 19 x 1.5 LH	Flammable Mixtures	Flammable Mixtures
LU 1	W 21.8 - 1/14" LH	Flammable	Hydrogen, Methane
LU 4	W 25.4 x 3.175" LH	Toxic	Hydrogen Cyanide
RI 2	G 22.91 x 1.814" RH	Oxidiser	Oxygen
RU 1	W 21.8 - 1/14"	Refigerants	Ammonia, Carbon Dioxide
RU 3	W 24.32 - 1/14"	Inert	Argon, Helium, Nitrogen
RU 4	W 25.4 x 3.175" RH	Toxic	Chlorine, Hydrogen Chloride, Sulphur Dioxide
RU 6	W 28.81 x 1.814" RH	Oxidiser	Air

UNI (Ente Nazionale Italiano di Unificazione)

Connector type	Connector description	Generic gas property	Example gases or mixtures components
UNI 4405	W 20 x 1/14" LH	Flammable	Hydrogen
UNI 4406	W 21.7 x 1/14"	Non Flammable / Oxidiser	Carbon Dioxide, Oxygen
UNI 4407	W 30 x 1/14"	Toxic	Ammonia
UNI 4408	W 1" x 1/8"	Toxic	Chlorine
UNI 4409	W 21.7 x 1/14"	Inert	Nitrogen
UNI 4410	W 30 x 1/14"	Non Flammable	Air
UNI 4411	W 22.9 x 1/14"	Flammable	Acetylene
UNI 4412	W 24.5 x 1/14"	Inert	Argon, Helium
UNI 9097	G 3/8" EXT	Oxidiser	Nitrous Oxide