Trailer Relay Valve For Semi Trailer Air Brake System

Emergency relay valve is a core safety component installed on semi-trailer air brake systems. It combines the functions of relay valve and emergency valve. During normal driving, it accelerates air filling and exhausting to shorten brake response time. Once the air pipeline ruptures, disconnects or there is air leakage between tractor and trailer, it will automatically cut off the air supply and trigger emergency braking immediately to prevent trailer runaway. Widely applied on heavy duty semi trailers, cargo trailers and large trucks.

Emergency relay valve is a critical safety component for semi-trailer air brake systems. It integrates the functions of a relay valve and an emergency valve into one compact unit. During normal braking, it accelerates air charging and discharging, reduces brake response time, and helps the trailer brakes engage more quickly and evenly. When an air line rupture, disconnection or serious air leakage occurs between the tractor and trailer, the emergency relay valve will automatically cut off the air supply and trigger emergency braking immediately, helping to prevent trailer runaway, loss of control and serious traffic accidents. It is widely used in heavy-duty semi-trailers, cargo trailers, container trailers, dump trailers and large commercial trucks.