沉降对地下燃气管道阀井内法兰泄漏的影响OA

For urban gas pipeline valve wells,it is proposed to use the equivalent pressure method for flange leakage verification.Using CAESAR Ⅱ V2014 stress analysis software,the calculated axial stress of the flange should be less than the rated pressure of the flange.Taking the buried gas pipeline valve well with design pressure of 1.0 MPa and DN 500 mm as an example,the calculation method of the maximum settlement that the pipeline can with-stand is given from the perspective of preventing flange leakage.According to different working conditions,the factors affecting flange leakage are analyzed.The cal-culation results indicate that the greater the settlement of the upstream and downstream pipelines of the valve well and the differential settlement rate of the pipeline section,the greater the axial stress of the flange,and the greater the risk of flange leakage.The construction should be avoided directly below the valve well as much as possible.