303.02.0031 Compatible 4-Circuit Protection Valve
303.02.0031
Summary
This heavy-duty 4-circuit protection valve is designed for heavy commercial vehicle brake systems. It features M22x1.5 and M16x1.5 port configurations, with specific opening pressures of 7 BAR and 6.5 BAR to ensure precise pneumatic control within the braking circuit. Equivalent to OE Knorr-Bremse AE4434 and MAN 81521516013.
| EAN Code | 8699031096285 |
|---|
Ready to Order
Compatible OEM Codes
-
MAN
- 81.52151-6069
- 81.52151-6066
- 81.52151-6057
- 81.52151-6013
-
KNORR-BREMSE
- II16098
- AE 4434
Description
What does a 4-circuit protection valve do?
This protection valve plays a critical role in the pneumatic braking system by dividing the air supply into multiple circuits to ensure safety through redundancy. By isolating circuit failures, it maintains braking capability in the remaining lines, which is essential for heavy commercial vehicle safety. Built with high-strength components, this part is engineered to withstand high-pressure fluctuations in demanding environments.Vehicle and system compatibility
The component is compatible with MAN vehicles and Knorr-Bremse systems. It ensures precise pressure regulation across all four channels to maintain system integrity during operation.Installation and technical specifications
For proper installation, technicians should verify the port sizes: Port 1 utilizes M22x1.5, while Ports 21 through 24 utilize M16x1.5. It is vital to check that the opening pressures—specifically 7 BAR for ports 21 and 22, and 6.5 BAR for ports 23 and 24—match the vehicle's technical requirements to ensure correct valve modulation.Maintenance and troubleshooting
Regular inspection of the pneumatic lines and connection points is recommended to prevent air leaks that could affect the closing pressures of the valve.OE cross-reference
303.02.0031 (4-circuit protection valve) is the equivalent of the Knorr-Bremse and MAN OE numbers. This part directly replaces Knorr-Bremse OE numbers AE4434, II16098. It also replaces MAN OE numbers 81521516013, 81521516057, 81521516066, 81521516069.Technical Specifications
| Port 1 | M22x1,5 |
|---|---|
| Port 21 | M16x1,5 |
| Port 22 | M16x1,5 |
| Port 23 | M16x1,5 |
| Port 24 | M16x1,5 |
| Opening Pressure 21 | 7 BAR |
| Opening Pressure 22 | 7 BAR |
| Opening Pressure 23 | 6,5 BAR |
| Opening Pressure 24 | 6,5 BAR |
| Closing Pressure 21 | 5,4 BAR |
| Closing Pressure 22 | 5,4 BAR |
| Closing Pressure 23 | 4,9 BAR |
| Closing Pressure 24 | 4,9 BAR |
Other OEMs
KNORR-BREMSE
- AE4434
- II16098
- AE 4434
MAN
- 81521516069
- 81521516066
- 81521516057
- 81521516013
- 81-52151-6069
- 81-52151-6066
- 81-52151-6057
- 81-52151-6013
- 81.52151-6069
- 81.52151-6066
- 81.52151-6057
- 81.52151-6013
Compatible Vehicles
| Brand | Model | Model Type | Engine |
|---|---|---|---|
| KNORR-BREMSE | |||
| MAN |
FAQ
What is the function of a 4-circuit protection valve?
It divides the air supply into four separate circuits, ensuring that a leak in one circuit does not lead to a total loss of braking pressure in others.
Which vehicle brands are compatible with this part?
This component is designed for use in MAN heavy commercial vehicles and is compatible with Knorr-Bremse systems.
What are the technical port specifications?
The unit features one M22x1.5 port (Port 1) and four M16x1.5 ports (Ports 21, 22, 23, and 24) for various circuit connections.
How can I identify if the valve needs replacement?
Technicians should look for signs of pneumatic leaks or a failure to reach the required opening pressures of 7 BAR or 6.5 BAR during system testing.
What are the OE reference numbers of this part?
303.02.0031 directly replaces Knorr-Bremse OE numbers AE4434, II16098. It also replaces MAN OE numbers 81521516013, 81521516057, 81521516066, 81521516069.