PA1012 Nylon for Air Brake Tubes, Hoses and Similar Components

PA1012 is a long-chain polyamide with low water absorption, excellent high and low temperature resistance, good flexibility, oil resistance and chemical resistance, making it the mainstream material for air brake tubes and hoses in automobiles and construction machinery. It fully complies with the standard QC/T 80-2022.

Core Properties of PA1012 for Air Brake Tubes

• Temperature resistance range: -60℃ to 130℃ (long-term service at 100–120℃, short-term up to 130℃)
• Low-temperature toughness: No brittle fracture at -40℃, stable in cold regions
• Low water absorption: Saturation water absorption approx. 2% (only half that of PA6), stable dimensions and durable pressure resistance
• Mechanical performance & flexibility: Tensile strength 50–70 MPa, elongation at break 150%–250%, small bending radius, easy routing
• Media resistance: Resistant to compressed air, brake fluid, lubricating oil, de-icing agents, no long-term swelling or aging
• Lightweight: Density 1.02 g/cm³, over 50% weight reduction compared with metal tubes
• Processability: Stable extrusion, suitable for single-layer / multi-layer composite tubes

Typical Applications

1. Commercial Vehicles / Heavy-duty Trucks (Mainstream)

• Main brake hard tubes / hose assemblies (straight / bent tubes, coiled tubes)
• Trailer connection air brake hoses, quick connectors, tees / crosses
• Connecting tubes for brake valves, relay valves, air dryers

2. Construction Machinery

• Pneumatic brake system tubes for excavators, loaders, forklifts, cranes
• Pneumatic control hoses for travel and steering systems

3. Other Vehicles & Equipment

• Brake lines for buses / light trucks, pneumatic systems for special vehicles
• Pneumatic control hoses for ships and rail transit

Structure and Specifications (per QC/T 80-2022)

• Structure: Single-layer extruded tubes, multi-layer composite tubes (PA1012 + adhesive layer + weather-resistant layer)
• Common sizes: Outer diameter 4–16 mm, wall thickness 0.8–2.0 mm, working pressure 0.8–1.25 MPa
• Connection: Compression fitting, quick connector, flared fitting

PA1012 vs PA11 / PA12 (for Brake Tubes)

Properties	PA1012	PA11	PA12	Advantages
Long-term heat resistance	100–120℃	100–110℃	100–120℃	Comparable to PA12
Low-temperature toughness	-60℃	-40℃	-50℃	Best cold resistance
Water absorption	2%	1.5%	1.5%	Close to PA12, much lower than PA6
Oil resistance	Excellent	Excellent	Excellent	Equivalent
Cost	Medium-low	High	Medium-high	Best cost-performance
Supply	Domestic sufficient	Mainly imported	Mainly imported	Stable supply chain

Material Selection & Processing Guidelines

1. Grade selection
   • Standard grade: General brake hard tubes, low-pressure hoses
   • Heat-stabilized / weather-resistant grade: Engine compartment, outdoor long-term use
   • Glass fiber reinforced (10–20%): High-pressure / large-diameter hard tubes for improved rigidity and pressure resistance
2. Extrusion parameters
   • Extrusion temperature: 230–260℃
   • Mold temperature: 40–60℃
   • Post-treatment: Annealing to relieve internal stress and improve dimensional stability
3. Compliance
   • Must comply with QC/T 80-2022 Road vehicles – Polyamide (PA) pipes for air brake systems
   • Key tests: Burst pressure, low-temperature impact, aging resistance, media resistance, dimensional stability

Summary of Advantages

• Safe and reliable: Wide temperature range, high toughness, media resistance
• Cost-effective: Performance close to PA12 at lower cost
• Easy installation: Good flexibility, small bending radius
• Lightweight: Weight reduction for improved energy efficiency.