large diaphragm, through Choke B, to the underside of the
large diaphragm and the quick action chamber in the pipe
bracket.
2.1.1.2 To the spring chamber of the selector valve.
2.1.1.3 To the brake pipe chamber above the large diaphragm
in the service valve.
2.1.1.4 To the emergency limiting valve, where the brake
pipe pressure overcomes the force of the spring and moves
the piston to its downward position permitting the check
valve to become seated.
2.1.1.5 Through Choke F and Passage 1a that leads to the
auxiliary reservoir charging check valve, where the auxiliary
reservoir is charged.
2.1.1.6 From Passage 1, brake pipe air flows through
Choke J into Passage lb that leads to the graduated release
cap and to the charging valve spool. The air continues to
flow into Passage 7a that leads to the selector valve spool
and passage 7b. From here the air may flow to the following
passages and chambers.
2.1.1.6.1 Through Choke H and into Passage 7 that leads
to the control reservoir chamber under the large diaphragm
of the service valve as well as to Port 7 in the pipe bracket
where the connection exists to the Reservoir Release Valve
Portion and the control reservoir.
2.1.1.6.2 Air flows around the selector valve spool valve
into Passage 9a and Choke G that leads to Passage 9.
This passage leads to the non-spring diaphragm chamber
of the selector valve, the selector valve spool, as well as to
Port 9 in the pipe bracket where the connection exists to
the selector volume reservoir.
2.1.1.7 When the air brake equipment arrangement of the
car is fully charged, identical pressure will exist above and
below the large diaphragm in the service valve. With the
aid of the large spring, the diaphragm assembly will remain
in its downmost position as long as the brake pipe pressure
remains stable.
2.1.2 BRAKE APPLICATION
2.1.2.1 To effect a brake application, the brake pipe pressure
in Port 1 MUST BE reduced. This reduction may be
manually initiated by movement of the Brake Valve Handle
on the controlling vehicle to the “Application” position or by
activation of another device which vents brake pipe air to
atmosphere.