Failure Analysis And Solution Of Sealing Ring Of Valve Cover And Head Sealing Ring

In the domestic petrochemical industry,the sealing rings of the cylinder valves in the high-pressure section of the primary unit of Yangba Petrochemical and Lanzhou Petrochemical Company have also experienced leakage of ethylene due to the failure of the sealing rings,while the sealing rings of the C1201E6 head of the primary unit of the high-pressure workshop of Maoming Petrochemical Company broke on October 20,2015,resulting in ethylene leakage.Leakage;in November 11,2015,ethylene was leaked due to carbonization of the O ring at the first six stages of the C1201 export.However,these ethylene leakage accidents are due to team operators found in a timely manner and properly handled,did not lead to major safety incidents.Because the compressor and its accessory equipment of the similar primary machine belong to the category of high-pressure equipment,once ethylene leakage occurs,the speed of ethylene leakage is extremely fast,and it is easy to produce the fire accident of ethylene flash explosion,so the reliability of sealing elements of high-pressure equipment is studied,so as to ensure the safe and stable operation of equipment,forever.Both are important research topics in the petrochemical industry.In view of these two failure accidents of sealing rings of high pressure equipment,the scientific and systematic analysis was carried out.First,the material composition of sealing rings was analyzed to find the material composition differences between foreign and domestic sealing rings,so as to judge the performance differences of sealing rings.The influence of three kinds of medium on the sealing ring in the working condition of primary engine and its auxiliary equipment;the third is to analyze the influence of pressure and temperature on the sealing ring according to the working condition of the sealing ring under different working pressure and temperature.Through scientific and systematic analysis,it is found that under the working environment with a small amount of propionic aldehyde,the sealing ring is less affected by low temperature and low pressure,low temperature and high pressure or high temperature and low pressure,and there is no obvious sealing failure characteristics;but under the combined action of high temperature,high pressure and propionic aldehyde,the sealing ring has obvious sealing failure characteristics.The phenomenon of chemical corrosion is easy to occur,and the aging speed of the sealing ring is accelerated,and the service life is shortened.The service life of O-ring of C1201E6 head of primary engine outlet heat exchanger is increased from 25 days to 15 months,and the service life of O-ring of 6-stage outlet valve cover of primary engine is increased from 1 month to 13 months.