relay valve

Relay valves are tested for durability before use through a seat test with air.

The relay valve's function is analogous to the transistor used in electronic circuits.

To correct this condition on a long-wheel-base vehicle, a relay valve is installed near the rear service brake chambers.

Relay Valve: Valve used to speed up the application and release of the rear wheel brakes.

On the electric side, pressure from a second straight-air trainline controlled the relay valve via a two-way check valve.

The pressure delivered to the service brake chambers in this manner will equal the control-pressure delivered by the foot-valve to the relay valve.

On the conventional side, the control valve set a reference pressure in a volume, which set brake cylinder pressure via a relay valve.

Instead of uneven braking pressure due to pressure loss through relay valves, you get even, consistent pressure applied simultaneously to all the brakes, all the time.

A spring brake relay valve works on the same principle as the service brake relay valve, although it has the opposite effect.

The delivery-port output of the parking-control valve connects to the control-port of this relay valve; this enables the spring brakes to be controlled via this valve.

A relay valve is an air-operated valve typically used in air brake systems to remotely control the brakes at the rear of a heavy truck or semi-trailer in a tractor-trailer combination.

As the DRS locos are unable to operate the vacuum brake on the GCR stock, our own D8098 is used for it's Air-Vacuum Relay Valve.

According to the agreement, SORL will develop braking valves and components fitted for light-duty vehicles, including brake chambers, air dryers, hand brakes, foot brakes and relay valves.

In tractors as well as straight-trucks, a remote air-supply is provided in the form of a large diameter pipe connected between the primary reservoir and the relay valve for remote service brake application.

In a truck's air brake system, relay valves get a signal when a driver presses the treadle, which then opens the valve and allows air to enter the brake chamber via air inlet.

The supply line receives air from the prime mover park brake air tank via a park brake relay valve and the control line is regulated via the trailer brake relay valve.

When the driver depresses the brake pedal, a small amount of air momentarily opens the relay valve's supply port, which then directs air from the remote air-supply directly to the rear service brake chambers, and quickly applies the rear service brakes.

Without relay valves, it would take too long for sufficient air to travel from the brake pedal valve to the rear of the truck or trailer in order to apply the rear service brakes concurrently with the front service brakes, resulting in a condition known as brake lag.

When the driver partially or fully releases the brake pedal, the control-pressure delivered by the foot-valve decreases; this causes the relay valve's supply port to close, and its exhaust port to momentarily open, thus preventing a pneumatic short-circuit from occurring while the air exhausts from all rear service brake chambers.