Fig. 1 Inversion Valve, Type SR-1

Fig. 5 Normal Broke Application, Primary and Secondary Systems Charged

TM-5-3820-256-24-4 Drilling System Well Rotary Truck Mounted Air Transportable 600 Feet Capacity Model LP-12 NSN 3820-01-246-4276 Manual
Page Navigation
130

SERVICE MANUAL Fig. 1 Inversion Valve, Type SR-1 1Delivery Port 2Supply Port 3Control Port 4Reservoir Port BENDIX SR-1 TYPE DESCRIPTION The inversion valve is used only on a straight truck with dual air brake system. Its purpose is to allow a modulated spring brake application if air loss should occur in the primary (rear) portion of the air system. The secondary (front) brakes cannot supply enough braking effort alone to stop the vehicle quickly to meet the FMVSS 121 requirements for emergency stopping. The inversion valve senses the loss of air in the primary system, allowing the spring brakes on the rear axle to be applied or released in a modulated manner at the same time the front service brakes are applied or released by the operator. The inversion valve also permits air pressure to enter the parking brake chamber releasing the spring brakes. The inversion valve is not required on tractor applications due to the fact the trailer brakes, being supplied with air from both the primary and secondary tractor systems, provide necessary braking required to meet FMVSS 121 emergency stopping requirements. 1Piston Spring 2Cover 3Large O-Ring 4Piston 5Small O-Ring 6Body 7Check Valve 8Check Valve Spring Guide 9Check Valve Spring 10Pipe Plug 11Exhaust Cover 12Diaphragm 13 Inlet & Exhaust Valve 14Cap Nut 15O-Ring 16Valve Stop 17Valve Spring 18Valve 19O-Rings 20Piston 21Piston Spring OPERATION Initial Air Charge (Fig. 3) Initial air charge from the primary and secondary reservoirs flows through the spring brake control valve and enters the supply port of the inversion valve. Air entering the support port flows past inlet and exhaust valve "B" to the underside of piston "B" and out delivery port to the emergency air connection on the spring brake chamber. Note that the springs above piston "B" force it into contact with inlet and exhaust valve "B." In the position shown the exhaust is closed and the inlet is open. Only air flowing from the primary reservoir enters the reservoir port on the inversion valve. This air remains under piston "A" as system pressure builds up. With primary reservoir pressure approximately below 379 kPa (55 psi) CTS-4079 - CHAPTER VII - Page 3

Privacy Statement
Press Release
Contact