The Failure Mechanism Analysis Of2Crl3/lCrl8Ni9Ti Safety Valve Used In Petrochemical Industry

Failure analysis is a result of the system or system components thathave lost all or partial functionality and failure is concrete and objectiveexistence. Therefore, failure is absolute, reliable relative. The failureanalysis of system or system components that have lost all or partialfunctionality when the results of reverse tracking or explore the reverse.It can help us early to predict and prevent the failure. On the basis ofthe failure emerged, failure analysis, and improvement, and then thefailure occurred, failure analysis, a further development, this upwardspiral of cognitive model explores the failure of the mechanisms, andintroduce a further measures of improvement and prevention. Failureanalysis has an important role in the development of the nationaleconomies and the building of national defense sciences andtechnologies. The prediction and prevention of the related technologieswill be more favorable to promote social progress and technologicaldevelopment.Safety valves device, as a system or system component, are toensure that the necessary components of the system are stable and safeoperation. The failure of safety valves will inevitably affect the stabilityof the system. Therefore, the failure analysis of safety valves is verynecessary and practical significance. The safety valve failure analysis isrelated to many factors, which is also a proper operation of safety valvewith the basic requirements, we can say that the safety valve that mustmeet certain functional indicators and working conditions, can workstable and reliable. The main content of this chapter is the analysis ofthe safety valve of the basic working principle and basic performanceindicators to establish the concept and basis for the failure analysis toprovide a basic reference for the safety valve. Compared with the specific summary of the work, in view ofinspection in the Changqing Oil Field, We found that the majority ofsafety valve relief valve flap failure caused by the failure of systemsand system components, and even lead to suspend production. Therefore,the relief valve flap failure analysis is necessary and meaningful tosuggest the improvements.In this thesis, anti-corrosion objects are2Cr13stainless steel oilsafety valve spool, the valve disc and the erosive medium of H₂S, Therequirements of the degree of its anti-corrosion under the originalconditions of use is in order to improve the life of the spool valve,reduce the valve damage, and increase the coefficient of the valve safeuse. With respect to the corrosion resistance of boiling hydrochloricacid vapor, the mass loss must be≤1.68/m₂·d and hot sodium hydroxidecorrosion≤5.08/m₂·d. The distortion resistance performance in thedifference in temperature of glass coating materials combinated with the2Cr13metal must be≥200oC. Experimental design of this condition asthe test direction.The Li₂O-B₂O₃-SiO₂glass system is determined according tocontrast test, The glass chemical composition marked5^#is used toprepare the anti-corrosion coating of2Cr13stainless steel. The glassthermal expansion coefficient, sintering temperature, coating sinteringtemperature, acid resistance and alkali resistance are109×10^-7℃-1,1230°C,850°C,0.19g/m₂·d and1.8g/m₂·h. In addition, the common useof ZnO and SrO, not only can increase the liquidity of the sinteredcoating, but also reduces the pinhole of the coating surface to preventsintering shrinkage, Which can be used as a safety valve anti-corrosioncoating to provide new ideas for the safety valve of steady use.