-
Denis,
The term tripple valve has been used by railroad personal from the
time the AB valve was introduced. This is due to the control valve
being made up of three pieces. The center section called the "pipe
bracket" where all the piping is contected. On one side there is
the "service portion" and on the other side the "emergency portion".
The release valve is attached to the service portion.

Jeff Coleman

-- In STMFC@..., "Denis F. Blake" <dblake2996@w...> wrote:

Guys

A quick explanation of valves on freight cars.

There is the control valve which controls the release of air from

the reservoir(s). A brake reservoir is broken into two parts. The
service side and the emergency side. The control valve controls
which side is used.

There is a retainer valve which has setting on it that determines

which "mode" of braking will be used on the car. The retainer valve
retains the air and allows various levels of brake exhaust during
normal application of brakes

Then there is the release rod which bleeds the air on the car that

is being held in the main reservoir AFTER the car is put into
emergency. Putting a car in emergency is what happens when an angle
cock on a car is left open and the car is cut away from the remainder
of the train. The emergency application of brakes will hold the car
for a period of time until the air still in the car bleeds off. It is
not acceptable to leave a car in emergency without having hand brakes
applied as well. This is probably the one that Tim is talking
about. It is a rod that extends from the side of the car, on both
sides, that is connected to a valve.

The control valve is what modelers commonly call a triple valve.

Control Valve is the proper name for this. Triple valve is a
modelers term.

Denis Blake
NS Conductor
Columbus, OH
----- Original Message -----
From: cf5250
To: STMFC@...
Sent: Tuesday, September 21, 2004 2:20 PM
Subject: [STMFC] Re: SP A-50-14 doors



Scott, do you mean the retainer valve, or the release valve?

Every car has a valve for dumping the air from the reservoir,
and there is a "release rod" reachable from either side of the
car. This is usually found in line with the AB valve on box
cars. Most modelers never bother with this even though it makes
a nice detail and is almost always visible from the side of the
car.

> can anyone say what that is below the side sill, just above the
builder's advertising sign in the builder's photo? I put the

control

valve there, even though that's a strange place for it.
> Scott Pitzer


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