Haldex 90555398 Pressure Protection Valve 90 PSI 1/4" NPT

The Haldex 90555398 is a pressure protection valve designed to protect the air brake system in heavy-duty trucks, trailers, and commercial vehicles. This critical safety component separates the auxiliary air system from the brake system, ensuring that adequate air pressure is preserved for braking in the event of a major leak or failure in the auxiliary system.

Key Features:

• Closing pressure: 90 PSI (6.2 bar)
• Opening pressure: 95 PSI
• All ports: 1/4" NPT female threads (inlet and outlet)
• Engineered to strict OE specifications for safety and performance
• Direct replacement for old or damaged valves
• Supersedes part numbers KN31004 and KN31010

This pressure protection valve is primarily designed to regulate air system pressure in tractors, trucks, and trailers, ensuring reliable brake system operation under all conditions. The valve closes at 90 PSI to protect brake system air supply and reopens at 95 PSI when system pressure is restored.