Dynamic model of analysis on a new type of guide-overflow valve;

Combination of overflow valve and by-pass valve in roots vacuum pump;

Reliability design for the pressure_adjusting spring of overflow valve based on the theory of fuzzy;

Study on a new type of G- π bridge pilot relief valve;

Couple analysis of relief valve and vibration control valve for hydraulic static pile-pressing machine;

Theoretical and experimental study on stability of G-π bridge relief valve;