What Is Air Brake Tubing?

Air brake tubing is a piping component used in commercial vehicle air brake systems. It transmits compressed air so that pneumatic pressure can be delivered to the braking devices.

Large vehicles such as trucks, trailers, buses, and tractor-trailers commonly use air brake systems as their primary braking method. These systems mainly consist of an air compressor, air reservoirs, control valves, braking devices, and tubing.

Straight air brake tubing is typically installed in fixed lines along the vehicle chassis and is commonly made of nylon to provide stable pressure resistance and adaptability to operating environments.

Main Standards for Air Brake Tubing

Commercial vehicle air brake tubing is mainly classified into two standard systems according to the vehicle market: DIN 74324 and SAE J844.

Both standards define dimensional specifications, material performance, and related technical requirements for air brake tubing to ensure the safe and stable operation of air brake systems during vehicle operation.

DIN 74324 (European Market)

DIN 74324 is a commercial vehicle air brake tubing standard mainly used for trucks, buses, and trailers in the European market. Its dimensional specifications are based on the metric system.

SAE J844 (North American Market)

SAE J844 is a commercial vehicle air brake tubing standard mainly used for trucks and trailers in the North American market.

This standard adopts an inch-based dimensional system and classifies tubing into Type A and Type B according to application conditions.

Comparison Between DIN 74324 and SAE J844

DOT FMVSS 106 and Air Brake Systems

In the North American market, commercial vehicle air brake systems are typically required to comply with the applicable requirements of DOT FMVSS 106.

DOT FMVSS 106 is a vehicle brake system safety regulation that mainly defines performance, testing, and identification requirements for brake hoses and related components. Air brake tubing compliant with SAE J844 may be used in vehicle air brake systems that meet DOT FMVSS 106 requirements.

Further Reading

→ Air Brake System Tubing Configuration

→ DOT Fittings

→ What Is the Difference Between Air Brake Tubing and Nylon Tubing?