Research on the Dynamic Characteristic of a Seawater-Hydraulic-Relief-Valve with a Damping Orifice

Seawater-Hydraulic-Relief-Valve (SWHRV) is a significant control component for Seawater-Hydraulic-System in underwater equipment. It makes the Seawater-Hydraulic-System operate within the relief pressure range and ensure the safety of the whole Seawater-Hydraulic-System. The performance of a SWHRV with an orifice and damping chamber is researched in this paper. The nonlinear mathematic model is built based on the operation principal and the visualization graphic simulation model is built by use of AMESim software. The simulation results indicates it has well static performances and satisfies the industrial requirements. Its rated opening pressure is 100 bar, and the releasing flowrate reaches 100 l/min when the pressure increase to 107 bar. The pressure adjusting range is between 100 bar and 205 bar. And the maximum releasing flowrate is as high as 1600 l/min at the pressure of 205 bar. Due to the damping orifice and chamber, a damping force would generate accompanying with the dynamitic motion of the spool. The opening dynamic characteristic is evidently improved though the shutting time becomes longer in comparison with the relief valve without orifice. The pressure oscillation is eliminated and it could reach the steady state ultimately. Furthermore, the effect of the damping orifice and chamber’s structure parameters on the dynamitic characteristic is analyzed. The orifice’s cross-sectional area is the main effect factor and the influence of the initial chamber volume can be neglected. Finally, the relief valve achieves well dynamic characteristic with the peak time 0.003 s and the transition time 0.015 s. The overshoot is about 20%. It has well performance with fast response, small overshoot and strong robustness.