QUADRA-dn2The QUADRA DN2 (internal diameter 2mm), flexible thermoplastic capillary hose, in two colors orange and black, represent the most efficient and developed system for the connection of pressure gauges, pressure switches and pressure test points. Transfer Oil advice the standardization of use of the QUADRA DN2 hose, choosing the orange color for the high pressure circuits and the black color for the low pressure circuits, so identifying in an unambiguous way the two parts of the circuit. This reduces the possibilities of misconnections of the two pressure lines of the machine during production and maintenance. The extraordinary number of QUADRA DN2 fittings covers all possible types of installations, making the need of copper rigid tubes and capillaries unnecessary. QUADRA DN2 hoses and fittings can be easily assembled using the specific QUADRA hand pliers RXA007, or the QUADRA CRIMP RXA006/RXA008.

Common technical data for DN2 – DN4 – DN6 hoses

Working pressure
Burst pressure
Working temperature
bar MPa psi bar MPa psi min°C max°C
120 12.0 1740 600 60 8700 -45° +130°

Performance and condition of use of DN2 hose↑ to top

Internal Diameter
Outside Diameter
Bend radius
Crimping diameter (pliers)
Crimping diameter (QUADRA-Crimp)
Hose Color Part number Pack ID (mm) OD (mm) Bend Radius (mm) Crimping diameter (mm) Crimping diameter (mm)


Hose coil


2 6,1 10 7 ± 0,1 7 ± 0,15




Hose coil




Permitted Fluids↑ to top

Type of Gas Type of Oil
HFC (R134a, R404A, R407A, R407B, R407C, R410A, R507) polyol ester based
HCFC (R22) mineral oils
CO2 polyol ester based

Classification of QUADRA capillary hoses according to Directive 97/23/CE↑ to top

Part No Classification according to Directive 97/23/CE
0780C paragraph 3 article 3

Permeability ↑ to top

The specification EN 1736:2008, among other various aspects, regulates the requirements to qualify the permeability rate of non-metallic tubes used in air conditioning and refrigerating systems, including heat pumps.
The permeability value provides an indication of the maximum leakage tested at constant conditions of use.
Permeability is measured in grams, permeated from a square meter of the internal surface of the hose during one year (g/m2 per year). The real permeability value must therefore be measured considering the actual working time and temperatures to which the hose is subjected.


Inner Tube

Thermoplastic polymer


Polyester braid of high tensile strength with high modulus


Thermoplastic polymer – orange or black – pinpricked – white ink-jet branding on black hose, black ink-jet printing on orange hose


Connection of pressure gauges, pressure switches and pressure test points


Light – Flexible – Compact – Vibration absorber

Temperature range↑ to top

-45 °C to +130 °C (-49 °F to +266 °F)

UV resistance

The test was made using a specific equipment called “Solar Box ERICHSEN mod. S1D (Xenon Lamp)”. The duration of the test has been 200 hours in total. The evaluation is based on the observation of the grey tones of the samples: the samples should not change their grey scale.
The evaluation is expressed on a scale from 1 to 5, where 1 is very bad and 5 is excellent. The orange sample achieved rating 4 (good). The black sample achieved rating 5 (excellent). Hence it follows that for all applications where the hoses are exposed to direct and frequent sunlight, black Quadra hoses are to be preferred.


Flexible thermoplastic capillary hose dedicated to the connection of pressure gauges, pressure switches and pressure test points in Air Conditioning and refrigeration systems. In contrast to the brazing or bending operations that are necessary for rigid copper tubing, installation and connection of QUADRA® flexible hose does not need any particular specialization and so making the connecting operation within anyone’s ability.