基于螺栓力的法兰接头泄漏率预测模型研究

摘要

Bolted flange joints are widely used in the petrochemical plants,and it is one of the weak locations for the occurrence of leakage.This is mainly because of the bolt force reduction.Thus bolt force is very important for the joints kept in sealing in service.Indexed with the leakage rate parameter,the relationship between the bolt force and gasket stress has been studied.The leakage rate model was established on the basis of bolt force.Corresponding experiments have been performed to verify this model.It was shown that with internal pressure increasing,the bolt force increases and gasket stress reduces,and there exists a monotonic relationship between the bolt force and gasket stress.The theoretical gasket stress value corresponds well with the experimental value.The calculated leakage rates for the joints also have a well agreement with the experimental value.Therefore,it is feasible to predict the leakage rate for the bolted flange joints by bolt force,and also this model is quite meaningful in monitoring the bolt force in the service of flange joint.%螺栓法兰接头在石化装置中应用广泛,也是频繁泄漏部位之一,主要是由于螺栓力不足导致密封垫片应力下降从而引起泄漏,因此接头运行过程中螺栓力变化对于其密封性能至关重要.针对该问题,提出以泄漏率为指标,研究法兰接头螺栓力与垫片应力的关系,构建基于螺栓力的法兰接头泄漏率模型,并开展接头螺栓力和泄漏率试验,验证模型可靠性.实验结果表明,随着内压升高,螺栓力增大、垫片应力下降,螺栓力和垫片应力存在单调对应关系,垫片应力理论计算值与试验值之间对应较好,接头泄漏率理论值同实验值相比具有较好的可比性.因此,基于接头螺栓力预测泄漏率是可行的,同时该模型对于监测法兰接头服役过程中螺栓力的变化具有重要的理论意义.