TM 5-3825-229-14&P
1-9. EQUIPMENT DATA (cont)
k. Spray Nozzle Control Valves.
Manufacturer . .......................................................................................... CLA - VAL Co.
Model No............................................................................................................ 7100 KH
Size ... ....................................................................................................................... 2 in.
Control system ......................................................................... Fluid actuated diaphragm
Section III. TECHNICAL PRINCIPLES OF OPERATION
Paragraph
Title
Page
Number
Number
1-10
SEMITRAILER ........................................................................................................................ 1-8
1-11
WATER DISTRIBUTOR SYSTEM ........................................................................................ .1 -9
1-10. SEMITRAILER
a. Electrical System. Includes 12-volt wiring for operating taillights and clearance lights. Power for semitrailer
lights is supplied from towing vehicle via a cable that must be connected by operator when semitrailer is coupled to
towing vehicle. The system is equipped with a 24-volt converter, providing capability for use with military or commercial
systems.
b. Brake System. Semitrailer service and emergency brakes are air-actuated brakes that are controlled from towing
vehicle. Air pressure for actuation is supplied by towing vehicle via two air hoses that must be connected by operator
when semitrailer is coupled to towing vehicle. Components of brake system that operator/crew must inspect and
maintain include the following:
(1) Gladhands. The gladhands are located at front of semitrailer. Gladhands are couplers that connect towing
vehicle air system to semitrailer air brake system interconnecting hoses.
(2) Air Reservoir Tanks. Two air reservoirs located beneath semitrailer store and maintain air pressure for
actuation of brakes. A drain cock is located in the bottom of each air reservoir. Purpose of drain cock is to drain
condensation (water) from tanks. This prevents water from entering semitrailer air system. Water can affect operation of
brakes and cause damage to components of air system. The drain cocks are opened by pulling on cables that extend
through frame between roadside tires.
(3) Spring Brake Chambers. These are mechanical devices that apply semitrailer brakes when driver steps on
brake pedal or pulls emergency brake lever in towing vehicle. Air pressure supplied by towing vehicle releases these
mechanical brakes. The chambers are spring loaded to apply brakes.
c. Landing Legs. The landing legs support semitrailer when it is not coupled to a towing vehicle. They are operated
by a hand crank. A two-speed gear box provides a low-speed gear for raising or lowering legs under a load, and a high-
speed gear for ease and speed of raising and lowering legs when not under
load.
1-8
