Quadra Capillary Hoses

The QUADRA flexible thermoplastic capillary hoses, 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 hoses, 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 fittings covers all possible types of installations, making the need of copper rigid tubes and capillaries unnecessary. QUADRA hoses and fittings can be easily assembled using the specific QUADRA hand pliers, or the all new QUADRA CRIMP.

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.

Availabale Sizes
- QUADRA DN2 (Inner Diameter 2mm)
- QUADRA DN4 (Inner Diameter 4mm)
- QUADRA DN6 (Inner Diameter 6mm)

Available in Two Colors Orange & Black
- Oranage color for high pressure circuits
- Black color for low pressure circuit

Common technical data for DN2 – DN4 – DN6 hoses

Working pressureBurst pressureWorking temperature

Permitted Fluids

Type of GasType of Oil
HFC (R134a, R404A, R407A, R407B, R407C, R410A, R507)polyol ester based
HCFC (R22)mineral oils
CO2polyol ester based

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.