Unique Fittings and Label Colors
Unique Fittings
A unique set of fittings is required for each and every refrigerant approved for use in motor vehicle air conditioning (MVAC) systems under EPA's Significant New Alternatives Policy (SNAP). These fittings are attachment points on the car itself, on all recovery and recycling equipment, on large refrigerant containers, and taps on small cans of refrigerant and other charging equipment.
The unique set of fittings for each refrigerant prevents the accidental mixing of different refrigerants. This helps protect the purity of the refrigerant in the MVAC system. An adapter may not be used to convert a fitting.
This list includes the most common refrigerants under SNAP, as acceptable, subject to use conditions, for MVAC as of May 21, 2012 for which unique fittings have been established. This table does not include GHG-HP/HCFC Blend Lambda or Ikon-12/Ikon A/Blend Zeta because unique fittings have not been developed or approved for those refrigerants. A table containing information on some legacy unique fittings and label colors can be accessed here: Legacy Unique Fittings and Label Colors (pdf) .
| Refrigerant | High Side Service Port | Low Side Service Port | 30-lb. Cylinders | Small Cans | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Diameter (inches) |
Pitch (threads/inch) |
Thread Direction |
Diameter (inches) |
Pitch (threads/inch) |
Thread Direction |
Diameter (inches) |
Pitch (threads/inch) |
Thread Direction |
Diameter (inches) |
Pitch (threads/inch) |
Thread Direction |
|
| CFC-12 | 6/16 | 24 | Right | 7/16 | 20 | Right | 7/16 | 20 | Right | 7/16 | 20 | Right |
| HFC-134a | quick-connect | quick-connect | 8/16 | 16 Acme | Right | 8/16 | 16 Acme | Right | ||||
| HFO-1234yf | Quick connect consistent with J639 (2020). Outside diameter 17 +0/-0.2mm. | Quick connect consistent with J639 (2020). Outside diameter 14 +0/-0.2mm. | 8/16 | 16 | Left | 8/16 | 16 | Left | ||||
| HFC-152a | Quick connect consistent with J639 (2011 version) | Quick connect consistent with J639 (2011 version) | ||||||||||
| R-744 (CO2) | Outside diameter 18.1 +0/-0.2 mm + | Outside diameter 16.6 +0/-0.2 mm + | 20.955 +0/-0.127 mm and right-hand thread direction | Not yet developed; additional information must be submitted to EPA.* | ||||||||
| R-744 (CO2) | Quick connect consistent with J639 (2011 version) | Quick connect consistent with J639 (2011 version) | ||||||||||
*Unique fittings have not yet been developed. Additional information must be submitted to EPA and unique fittings must be approved prior to commercialization.
+HFC-152a and R-744 service fittings are provisional pending final production, commercialization and use of the refrigerant.
Label Colors
Historically, EPA established a specific label color for each refrigerant as part of its SNAP approval. The table below includes only those refrigerants for which EPA required use of a specific label color as part of the listing decision. This table does not include all MVAC refrigerants, such as those for which labeling was never developed. Also, the use conditions for HFC-152a, R-744 (CO2) and HFO-1234yf require compliance with SAE J639, which specifies the markings required on labels, but not unique label colors. These refrigerants are not included in the table below and must be labeled in accordance with SAE J639.
| Refrigerant | Background |
|---|---|
| CFC-12 | White
|
| HFC-134a | Sky Blue
|