| This dissertation consists of two parts. The first part is concerning the service life analysis of drilling pump valve. By studying on the fatigue life of a drilling pump valve, a further elucidation is made on the main failure mechanism of the valve. With the software ANSYS/LS—DYNA, a 3D solid model is built, which simulates the process when the valve disc is impacting the valve seat and produces the stress pattern of valve disc. According to the simulative result, the effect of pulsating stress on the fatigue damage of drilling pump valve is analyzed, which focuses on the harm that stress concentration may accelerate pump valve failure when under alternating load, improving the non-impact theory. Finally, the service life of the valve is estimated based on the fatigue curve and an improvement scheme of pump valve structure is also presented which can effectively alleviate the stress concentration and extend the service life.The other part is concerning the research on vibration control of piping system. Aiming at the problem in a plant that severe vibration exists in the outlet pipeline of centrifugal compressor, resulting in frequent failure of the outlet technological system. This dissertation uses CAESARⅡand MATLAB software to calculate the dynamic characteristics of the gas piping system (gas column natural frequency, gas pulsation), the dynamic characteristics of mechanical structure (natural frequency, vibration mode) and the stress caused by weight and thermal expansion. The cause of piping vibration is analyzed and confirmed combined with results from spot investigation, and then measures are taken to reduce the vibration. Finally, aiming at the exceeding of compressor nozzle load, a variety of methods is presented to reduce the stress and meet the requirements of equipment operation. In this dissertation, optimal design method of vibration control and the specific reform measures can be directly applied to the practical production.
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