Abstract: The flow resistance coefficient and opening force are the most important parameters for the evaluation of valve performance. In consideration of the influence of noise reduction optimization on the internal flow passage of pilot operated valve, the CFX software is used to simulate and analyze the flow resistance coefficients under different external working pressures and openings. The analysis results show that the flow resistance coefficient of optimized flow passage is less than that of the original flow passage for the valve under low and full openings. The valves with and without pilot hole are also statically analyzed by CFX software under different openings. the surface groups for extracting are determined according to the influence surface of actual valve rod axial force, and the axial forces of valve rod in different positions are obtained. The analysis results indicate that the pilot hole can reduce the opening force, and the maximum opening force of value with pilot hole is an half of that of value without pilot hole. The simulated opening force is validated by experiment, and the experimental result is consistent with the simulation result.

Key words: ordnance science and technology, pilot-operated, outboard valve, flow resistance coefficient, opening force