Air-Line Fittings

This article is a compendium of hand-operable air-line fittings, typically of quick-disconnect type, used for pneumatics and other compressed air purposes including breathable air (a subset of breathing gases).

Breathable air applications

For breathable air applications such as SCBA, these may found on both sides of the first-stage and second-stage pressure regulators (very similar to SCUBA diving regulators) to allow for rapid and tool-free return-to-service. For breathable air applications such as supplied-air and mixed supplied-air with SCBA backup, the quick-disconnect fittings allow movement of a worker from one supplied-air station to another.

Other applications

These fittings or special-service variants may also be found in hydraulic applications and alternative compressed gas applications (Oxy-acetylene welding and cutting, fuel gases, NSF C-2 food-contact, etc...), though perhaps not as frequently.

Summary tables of fittings, alpha-sorted by common fitting name

Table 1

In many instances the name is the manufacturer who originated or popularized a particular design.

Fitting Name Alternate Names and Notes Male Plug Fitting Female Socket (coupler)
CEJN
Duff-Norton
Foster
Hansen 2-HKIG White acetal identifier ring on body of fitting
Hansen 2-HKIL Black acetal identifier ring on body of fitting
Milton
Parker
Schrader Twist-Lock Found on older MSA SCBA gear Tapered cone Pair of semi-circular jaws
Snap-Tite
Tomco

(see also: ARO, Automotive, Broomwade InstantAir, Camel, Coilhose, Tru-Flate, Walther, etc...)

Table 2

Summary table of cross-compatible "meta" fitting designs, specifications, or profiles, alpha-sorted by common fitting name.

Fitting Name Male Plug Fitting Female Socket (coupler) Connection Design
ARO Interchange Profile (Green) Longer nose One thick stripe on body of fitting
Automotive Interchange Profile (Blue) Shortest nose One thin stripe on body of fitting
Industrial Interchange Profile (Red, ISO 6150-B, US-MIL-SPEC-C-4109) Shorter nose Two thin stripes on body of fitting
Lincoln Interchange Profile (Lincoln Industrial Corporation→ Content 2.2 The Lincoln 815 Air Coupler) also called Flex-O-Matic, Long Nose, Lincoln Series, and Type L or Style L Longest nose One thick stripe and one thin stripe on body of fitting Semi-Automatic
Semi-Universal Interchange Profile (ARO, Automotive, Industrial) not applicable Three thin stripes on body of fitting

(see also: British Profile, English Industrial profile, Italian Profile, Japanese Profile, 7.2 - 7.4 European Profile, ISO 6150-C)

References