Outlet hose must be 3/4-inch diameter with 1/2inch
of the control of the flow of brake pipe air through the
connecting nipples and must not be more than 8 feet
choke to the brake cylinder. Some equipment has been
manufactured without the choke plug but with the
auxiliary reservoir tapped for insertion of the plug later,
(4) In the event of valve falling to pass the
if desired. Consequently, on such equipment, the quick
specified test, it should be ascertained that the single-
car testing device is not at fault. If the device is not at
8-28. Single-Car Testing Device
a Operation. The purpose of the single-car testing
(5) Care should be exercised in moving the
device (fig 8-51) is to provide a means for a general
test device handle back to position No. 3 (lap) after
check on the condition of the brake equipment on "in-
making brake pipe reductions of 15 pounds or more in
date" cars while in service and on cars which have
position No. 5 When snapped back, the temperature
undergone periodic repairs without the removal of any
effect will cause the brake pipe pressure to rise 1 1/2 to
device from the car.
2 pounds and may be the cause of an undesired
release. The device handle should be moved slowly
(1) There are two types of single-car testing
toward lap position.
devices which are similar in appearance. One is for
passenger cars and the other for freight cars. The
(6) When making tests of cars having two
passenger device can be identified by a nameplate
sets of brake equipment, each set must be tested
marked PASS, while the freight device is marked FRT.
separately, with the branch pipe cutout cock closed to
Freight device is now equipped with a flowrator to check
one set while the other set is being tested. A complete
flow of air through device.
test (including brake pipe leakage on passenger cars)
must, however, be made with each set of equipment
(2) The single-car testing device arrangement
unless the passenger single-car testing device with
must include a suitable feed valve or reducing valve in
flowrator is used. If both sets are connected to use one
the supply line for the purpose of providing a constant
common brake cylinder release valve, it will also be
pressure source as defined in the test codes and an
necessary to blank off the 3/4-inch brake cylinder pipes
efficient air filter in the supply line ahead of the feed
at both the control valve and the brake cylinder on the
set not being tested. This may readily be done by
temporarily inserting 1/16 by 1 7/8-inch blanking plates
(3) The use of a hose is optional between the
between the flanged fittings and the bolting faces.
testing device and the outlet hose coupling which
connects to the brake pipe hose on the car.
Figure 8-51. Freight single-car testing device with flowrator.