3.9.5 Check and adjustment of pneumatic system pressure regulator

3.9.5 Check and adjustment of pneumatic system pressure regulator

It is necessary to adjust the pneumatic system pressure regulator during maintenance MS3, and also when the pressure regulator operation is disturbed as well as after its disassembly for washing or for replacement of worn out parts. Check and adjustment of the pneumatic system pressure regulator should be made after adjustment of service brake control, of parking brake control and brake valve actuator.

Check the pneumatic system pressure regulator in the following order: - connect the pressure gage (with scale factor of 0,01 …0,02 MPa and scale at least up to1,6 MPa) to the connecting head with red cover; - take off a cap 1 (figure 3.9.6); - using a wrench screw a cover 2 to the casing against the stop; - turn the pneumatic compressor on; - start the engine and fill the tank with compressed air until a safety valve 7 is actuated at pressure of 0.85… 1 MPa. If the valve is actuated at pressure less than 0.85 MPa or more than 1 MPa, make its adjustment with a screw 9, having previously loosened and then having tightened a lock-nut 8. Adjust the pneumatic system pressure regulator in the following order: - gradually unscrewing of the cover 2, adjust force of springs 3 and 4 so that air pressure in the tank, at which a relief valve 6 opens, made 0.77 to 0.8 MPa; - mark this position of the cover 2 using paint applied on a treaded part of the casing and put the cap 1; - slightly open the condensate drain valve in the tank and reduce air pressure to 0.65 …0.7 MPa. At this pressure values the valve 6 should close and switch the pneumatic compressor over to tank filling with compressed air; - disconnect the test pressure gage from the connecting head.

1 – cap; 2 – cover; 3 – outer spring; 4 –inner spring; 5 – filter; 6 – relief valve; 7 – safety valve; 8 – lock-nut; 9 – adjusting screw. Figure 3.9.6 – Pneumatic system pressure regulator Note: Filter 5 (figure 3.9.6) is mounted only in the regulator 80-3512010. The other regulators of the pneumatic system do not have the filter mounted.