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303.02.0069 Compatible 4-Circuit Protection Valve

303.02.0069

Summary

This 4-circuit protection valve is designed for heavy commercial vehicle brake systems. It features M22x1.5 and M16x1.5 port configurations, with a maximum operating pressure of 20 BAR, ensuring reliable pneumatic circuit division and safety. Equivalent to OE Knorr-Bremse AE4421.

Product identifiers
EAN Code8683457009288
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Compatible OEM Codes

  • KNORR-BREMSE
    • AE 4421

Description

This protection valve plays a critical role in the pneumatic brake system by dividing the air supply into multiple independent circuits. By isolating pressure drops in one circuit from others, it ensures that even if a single line fails, the remaining circuits maintain sufficient pressure for safe operation. This component is engineered with high-strength components to withstand heavy-duty commercial vehicle demands.

The unit is compatible with Knorr-Bremse systems and is designed for integration into complex pneumatic networks. It manages various pressure thresholds, including specific opening pressures of 7.6 BAR and 6.7 BAR for different ports, to ensure precise air distribution across the vehicle's braking infrastructure.

Technicians should verify all port connections, specifically the M22x1.5 and M16x1.5 threads, during installation to prevent leaks. Regular inspections of the opening and closing pressures—ranging from 4.3 BAR to 5.5 BAR depending on the port—are essential for maintaining optimal braking performance and system safety.

Consult your authorized distributor to ensure correct fitment for your specific pneumatic configuration.

OE cross-reference

303.02.0069 (4-circuit protection valve) is the equivalent of the Knorr-Bremse OE number. This part directly replaces Knorr-Bremse OE number AE4421.

Technical Specifications

Technical Specifications
Port 1M22x1,5
Port 12M16x1,5
Port 21M16x1,5
Port 22M16x1,5
Port 11M16x1,5
Port 23M16x1,5
Port 24M16x1,5
PressureMAX 20 BAR
Opening Pressure 217,6 BAR
Opening Pressure 227,6 BAR
Opening Pressure 236,7 BAR
Opening Pressure 246,7 BAR
Closing Pressure 214,3 BAR
Closing Pressure 224,3 BAR
Closing Pressure 235,5 BAR
Closing Pressure 245,5 BAR

Other OEMs

KNORR-BREMSE

  • AE4421
  • AE 4421

Related Products

Compatible Vehicles

Compatible Vehicles
BrandModelModel TypeEngine
KNORR-BREMSE

FAQ

What is the main function of this protection valve?
It divides the air supply into four independent circuits, ensuring that a leak in one area does not compromise the entire braking system's ability to stop the vehicle.
What are the port specifications for this component?
The valve features one M22x1.5 port and multiple M16x1.5 ports to facilitate standardized connections within heavy commercial vehicle pneumatic systems.
What is the maximum operating pressure?
This component is rated for a maximum operating pressure of up to 20 BAR within the pneumatic braking circuit.
How can I identify if a replacement is needed?
Technicians should check for irregular opening/closing pressures or air leaks at the M22 or M16 ports during routine system inspections.
What are the OE reference numbers of this part?
303.02.0069 directly replaces Knorr-Bremse OE number AE4421.