Calibrated Polyamide Tube Medifly PATR912 Black (Ø 9×12 mm, PA12 TRUCK, Black)

1. Purpose and Operating Principle

The black color and PA12 TRUCK compound with carbon-black additives protect the material from UV degradation and de-icing road salts — the tube is designed to run under a truck’s or trailer’s chassis, in direct contact with road chemicals and salt solutions. The high 70 ShD hardness combined with a thick 1.5 mm wall delivers a working pressure of 21 bar — substantially higher than standard general-purpose pneumatic tubing.

2. Technical Specifications

3. Design Features

Decoding the Medifly PATR912 Black code:

Key design solutions:

• Certified for brake systems — the Medifly PATR series is designed and certified to DIN 73378 and DIN 74324 specifically for commercial-vehicle brake circuits, rather than adapted from general-purpose tubing.
• High working pressure — 21 bar working pressure and 65 bar burst pressure give a substantial margin over typical pneumatic brake system parameters.
• Resistance to harsh outdoor environments — carbon-black UV-stabilizing additives in the black PA12 protect the tube during years of operation under the chassis, including contact with de-icing road chemicals.
• Wide temperature range (−60°C to +80°C) — designed for cold-climate operation and for proximity to brake assemblies where localized heating may occur.

4. Installation Recommendations

1. End preparation. Use a dedicated guillotine-style tube cutter for a clean 90° cut — this is especially critical for brake lines, since even slight end deformation can cause a leak at the fitting under 21 bar working pressure.
2. Fitting types. Compatible with push-in and compression fittings of 12 mm, certified for commercial-vehicle pneumatic brake systems.
3. Bend radius. Minimum bend radius is 100 mm; do not allow sharper bends when routing along the chassis.
4. Routing and fixation. Secure the tube at regular intervals along the chassis, avoiding points of friction against metal and sharp edges — despite the material’s resistance, mechanical abrasion against the frame remains the main risk over long-term operation.

5. Common Mistakes

• Using a general-purpose tube instead of certified PATR tubing — tubes without DIN 73378/74324 certification are not intended for brake circuits and don’t guarantee the required safety margin.
• Installing without observing the 100 mm minimum bend radius — can pinch the bore when routing through tight spots on the chassis.
• Cutting with a substandard tool — an uneven end causes a leak at the fitting under high working pressure.

6. Applications

• Pneumatic brake systems of trucks — main and connecting lines.
• Trailers and semi-trailers — brake circuits designed for under-chassis operation in any weather.
• Commercial vehicles in general — anywhere a DIN 73378/74324-certified tube with elevated working pressure is required.

7. Expert Opinion

Vitalii Boluchevski, lead engineer at Acvatron SRL (18 years of experience): “The Medifly PATR912 Black polyamide tube at 12×9 mm caliber is the primary mainline standard for pneumatic brake systems in commercial road transport.”

8. FAQ

1. Is the PATR912 tube suitable for a trailer’s main brake circuit? The Medifly PATR series is specifically designed and certified to DIN 73378 and DIN 74324 for commercial-vehicle brake systems.

2. What’s the maximum working pressure the PATR912 tube can withstand? At +23°C, the working pressure is 21 bar, and the burst pressure is 65 bar.

3. Can this tube be mounted outdoors, under the chassis? Black PA12 contains special carbon-black additives that protect the material from UV degradation and de-icing road chemicals.

4. What coil size is the tube supplied in? Standard packaging is a 100-meter coil.