The level control valve NRV -0.1 is a mechanical working relief
valve. By increasing the mass the control rod of the control
valve moves down. The reversing shaft rotates clockwise. compressed
air flows from the P-connection to the A-connection and the
air spring system will be filled with compressed air. By decreasing
the load on the seismic mass the control rod of the control
valve moves upside and the reversing shaft rotates anticlockwise.
Compressed air flows from the A-connection to the R-connection
and escapes into the ambiance.