TM 5-3825-226-24PROTECTION UNIT OF THE CONTROL VALVE(AA from illustration 54669Xl)1.Opening for wet tank. 3. Opening for reserve tank. 5.Opening for dry tank. 14. Exhaust passage. 15. Valve. 16.Piston. 17. Spring. 18. Spring. 19. Passage for inlet. 20.Check valves.The passage (I) to the wet tank gives protection to thepassage (3) and (5) reserve and dry tanks. If the pressurein the passage ( I ) to the wet tank goes down to 40 + 5 psi(280 + 35 kPa), the protection unit activates automatically.Now, spring (18) for emergency piston (16) moves. Whenpiston (16) moves it will move valve (15). Exhaustpassage (14) of the protection unit is sealed and inletpassage (19) lets air from passage (3) or passage (5)gointo the area above piston (16) and causes piston (16)tomove. Piston ( 16) makes the basic part of the controlvalve work like the system was operated manually. Theprotection unit has check valves (20) which stops air fromgoing out of one side through the other side because of afailure in either line. If the air pressure goes below 50 ± 5psi (345 ± 35 kPa) in passages (3) or (5), the emergencybrake will also activate when passage (I) has full pressure.Brake Control ValveThe control valve for the tractor and water distributorbrake systems has separate passages for supply air anddelivery air. The same amount of air is delivered to bothsystems. But, a failure of either system will not affect theoperation of the other part of the valve. The upper partofthe valve is used to control the tractor brakes and thelower part of the valve is used to control the waterdistributor brakes.2-132
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business
