B46.20-0039-01
1 Threaded body
2 Control valve
3 Compression spring
4 Oil return duct
5 Oil supply duct
Operation
The hydraulic pressure actuating on the supply duct (5) acts on the control valve (2) against the elastic pressure of the counter pressure spring (3). If, in supply duct (5), the pressure generated by the oil pressure exceeds the opposing pressure of the counter pressure spring (3), the control valve (2) will move and open up a small groove.
The surplus amount of oil supplied by the power steering pump is driven through this groove to the return duct (4) and hence to the oil tank.
The limitation of the maximum pressure in the steering system is a consequence of the size of the groove which, in turn, is controlled by elastic pressure of the pressure spring (3).
The rated pressure of the pressure relief valve is set in hexagonal head..