INDIAN RAILWAYS – INDEPENDENT BRAKE VALVE
The SA – 9 Independent Brake Valve is a Self – lapping independent brake valve which performs graduated application or release of locomotive brakes independent of the automatic brake valves. It is also capable of releasing an automatic brake application on the brakes.
The brake valve has three position : “Quick Release”, “Release”, and application. The SA – 9 Independent brake valve consist of a Self – lapping portion which when actuated, supplies or exhausts air pressure for piloting the graduated application or release of brake cylinder pressure on locomotive. This valve also includes a release valve, which serves to release an automatic brake application of the locomotive brakes, independent of the train brakes, when the brake handle is placed in the “Quick Release” Position.
OPERATING CHARGING
In the “Release” Position of the brake valve handle the inlet valve, is positioned at its farthest travel from the regulating valve diaphragm assembly. The inlet valve assembly will carry the double ball valve away from the regulating valve diaphragm. The double ball valve will be unseated at the exhaust while being seated at the inlet by the inlet valve spring. With the exhaust valve open, any air pressure in the independent application and release pipe connected to port 20 will be exhausted to atmosphere.
Main reservoir air is supplied through port 30 to the spring chamber of the inlet valve vacuum brake pipe is connected through port 1 of the spring chamber of the Quick Release Valve and control valve Vacuum reservoir connected to port 7, where it is blanked due to the position of the Quick release valve.