Development of a direct pressure-sensing pressure-reducing valve for water hydraulics

This paper submits a new design for a pilot-operated pressure-reducing valve for water hydraulics. The developed valve operates with a primary pressure of up to 14 MPa, secondary pressure range of down to 3.5 MPa, and a flow range of 2.7 to 15 l/min. The major features of the designed valve are: the main valve has two serial throttles to prevent cavitation, the pilot valve detects the secondary pressure directly, seepage from inlet port to pilot chamber is removed, and a viscous damper stabilizes the motion of the valve. A valve was produced whose dimensions were determined according to dynamic and static analyses. Experimental studies were carried out on the produced valve. No cavitation noise was observed for primary pressure up to 14 MPa. The steady state characteristics of the produced valve agreed well with the prediction by simulation. The measured secondary pressure variation was about 0.2 MPa at the maximum for the primary pressure of up to 14 MPa, and about 0.5 MPa for the flowrate up to 15 l/min.