Four-Circuit Protection Valve

Description：High-quality four-circuit protection valve for SINOTRUK HOWO and other heavy trucks. Separates air brake circuits for safety and reliability. OEM compatible, durable aluminum housing, pressure-tested and ready to install.

Product model：

Category ：Brake System

Update time：2025-06-30

Product Introduction

The four-circuit protection valve is an essential safety component in the air brake system of SINOTRUK and other commercial vehicles. It divides the compressed air supply into four separate circuits—typically front axle service brake, rear axle service brake, parking brake, and auxiliary devices—ensuring that a failure in one circuit does not affect the others. This provides enhanced operational safety, air management efficiency, and brake reliability.

Designed specifically for SINOTRUK HOWO series and compatible with other major Chinese truck brands like SHACMAN, FAW, Dongfeng, this valve conforms to WABCO-type standards and supports direct OEM replacement

Technical Specifications

Parameter	Specification
Operating Pressure	0.8 – 1.0 MPa
Number of Circuits	4 (Front Service, Rear Service, Parking, Auxiliary)
Port Thread Size	M22×1.5 / G1/2 (customizable)
Housing Material	Aluminum alloy with anti-corrosion finish
Voltage Support	24V air brake systems
Operating Temperature	-40°C ~ +80°C
Application	SINOTRUK HOWO, SHACMAN, FAW, Dongfeng, trailers, buses
Replacement Reference	WABCO 9347140100 / KNORR equivalents