4-circuit protection valve

4-Circuit Protection Valve — Brake System Air Circuit Management

The 4-circuit protection valve is a critical safety component in the brake system group of heavy commercial vehicles, independently supplying and protecting air pressure circuits. It distributes pressurized air from the compressor to four separate circuits—for example, front brake, rear brake, parking brake, and auxiliary circuit—protecting the pressure in other circuits even if one circuit develops a leak or malfunction, preventing the vehicle from losing all braking capability. In this way, it serves an indispensable safety function in trucks and buses carrying heavy loads, preventing pressure loss at any point in the system from affecting the entire vehicle.

The product range includes complete 4-circuit protection valve assemblies, repair kits, gaskets, springs, valve bodies, and connection components. Wide options are offered to suit different pressure stages, circuit counts, and mounting configurations, ensuring perfect compatibility with the vehicle's original system. Suitable alternatives are available for both new vehicles and older models requiring maintenance.

• Complete 4-circuit protection valve assemblies
• Repair and maintenance kits
• Gasket, spring, and sealed cover sets
• Connection, valve body, and mounting accessories

These components, manufactured with general compatibility with major truck and bus brands, require regular maintenance and timely replacement to maintain proper pressure balance. When selecting, the vehicle's circuit count, pressure range, and connection type should be considered; a product conforming to original specifications should be chosen to prevent performance loss. Inspecting the component promptly when symptoms such as leaks, delayed brake response, or unbalanced pressure are detected is critical to keeping the vehicle operating continuously on the road.

Frequently Asked Questions

Which circuits does the 4-circuit protection valve protect? It independently supplies and protects four separate air circuits, such as front brake, rear brake, parking brake, and auxiliary circuit.

What happens if the 4-circuit protection valve malfunctions? Pressure loss or a leak may occur in the affected circuit, but the other circuits are protected, preventing the vehicle from losing all braking capability.

Which components does the 4-circuit protection valve work with? It works in coordination with brake system components such as the air tank, ABS, and dual circuit check valve to ensure balanced circuit supply.

When should the 4-circuit protection valve be replaced? It should be inspected and replaced if necessary when pressure imbalance, continuous air leakage, or delayed brake response is observed.

What should be considered when selecting a 4-circuit protection valve? The circuit count, pressure range, and connection type should be selected to match the vehicle's original specifications.

How is the 4-circuit protection valve maintained? Air leakage and pressure should be checked at regular intervals, and worn gaskets and seals should be replaced promptly.

Does the 4-circuit protection valve operate the same way in all commercial vehicles? General compatibility is provided with major truck and bus brands, but the model selection may vary depending on circuit configuration.