Description
Secure your commercial fleet’s air brake system against catastrophic pressure loss with the genuine Knorr-Bremse Air Brake Pressure Protection Valve. Engineered by global braking leader Knorr-Bremse, this critical safety valve monitors compressed air distribution across multiple independent circuits (service brakes, parking brakes, and auxiliary accessories), automatically cutting off secondary air drains if a primary line ruptures. Worn internal check valves, sluggish springs, and pneumatic leaks eventually compromise air containment, leading to low system pressure warnings and dangerous brake failure. This heavy-duty replacement pressure protection valve solves those issues directly. It utilizes high-precision calibration springs, corrosion-resistant valve bodies, and robust rubber seals to deliver reliable circuit priority control, ensure fail-safe braking pressure, and withstand severe commercial transport abuse.
Technical Parameters
| Category | Specifications & Technical Details |
| Multi-Circuit Intelligent Air Pressure Priority Allocation | During engine start-up and air charging, the valve prioritizes filling the service brake main circuits (front / rear axle) and parking brake system. Only after main air pressure reaches the safety threshold does it supply auxiliary circuits such as suspension and horn. |
| High-Precision Cracking & Closing Pressure Calibration | We integrate a high-fatigue-life calibrated spring inside the valve. It achieves extremely precise valve opening and cut-off at preset pressure points (such as 6.5 bar to 7.5 bar), ensuring compliance with international commercial vehicle pneumatic safety regulations. |
| Single-Circuit Failure Isolation & Anti-Leakage Protection | When an auxiliary air line or accessory suddenly ruptures and leaks, the valve instantly and automatically closes that branch circuit. It locks the compressed air inside the main brake reservoir, guaranteeing the vehicle still maintains full braking capability. |
| High-Anti-Aging Nitrile/Viton Dynamic Sealing Barrier | We manufacture all internal pistons, one-way valve cores, and diaphragms from specialty cold-resistant, oil-resistant elastomer material. They maintain high-elasticity sealing under extreme climates from -40°C to +80°C, eliminating internal air cross-leakage. |
| Industrial Corrosion-Resistant Die-Cast Aluminum Body | We build the valve body from high-strength lightweight die-cast aluminum alloy and apply surface anodizing and passivation treatment. It perfectly resists oxidation corrosion caused by de-icing salt, road moisture, and high-pressure washing. |
Applicable Car Brands & Models
Common warning symptoms include:
Slow System Charging on Startup: The air pressure gauges take an unusually long time to rise to operating pressure when starting the engine.
Pressure Drop in Primary Circuits: One air circuit loses pressure rapidly while auxiliary systems drain the remaining air.
Persistent Low-Pressure Dashboard Alarms: Frequent buzzer or light warnings triggered by failure to maintain safe operating thresholds.
Audible Air Leaks Inside the Chassis: Hissing sounds coming directly from the protection valve block during system operation.
While Knorr-Bremse provides internal seal kits for general overhauls, the critical cracking and closing pressures are factory-calibrated using precision equipment. If the internal springs lose tension or the valve body is worn, complete valve replacement is strongly recommended to guarantee legal and operational safety.
Yes, absolutely. After installation, technicians must use a pressure gauge test manifold to verify that each circuit opens and closes at the exact manufacturer-specified PSI/bar ratings, and check all port fittings with soapy water to ensure zero air leaks.
Each protection valve is fitted with heavy-duty plastic plugs over all threaded air ports to block moisture and debris, wrapped in anti-corrosion barrier film, and packed inside a reinforced branded industrial box to protect the precision pneumatic components during global transit.

























