管道压力试验时对膨胀节的临时约束及其强度校核

Temporary Restraint and Strength Calibration on Expansion Joint at Pipeline Pressure Test

管道安装后进行压力试验时,施工验收规范要求要对管道上的膨胀节进行临时约束。约束的形式有采用螺杆和门形钢板两种。对临时约束的方法措施通过受力分析及强度校核计算进行比较,证明采用门形钢板加固方式使膨胀节出现了拉伸变形,加固的门型钢板产生了弯曲和拉伸塑性变形,容易造成事故。采用螺杆连接的加固方法螺杆只承受轴向拉力,不产生弯矩,应推荐使用。为相同企业在管道试压时提供借鉴。

In accordance with construction acceptance specification,temporary restraint is to apply to the expansion joint on pipeline at pressure test after pipe installation.There are two types of restraint-screw rod type and frame plate type.The temporary restraining method is analyzed on the force bearing and is calculated and checked on the strength.It is proved that the expansion joint reinforced by frame plate shows tensile deformation,and the stiffed frame plate bends and presents tensile plastic deformation.In this case,incidents are susceptible.By means of screw rod reinforcing method,the screw rod only bears axial tension and doesn’t generate bending moment.This method is recommended.The paper gives a reference of pipeline pressure test to other enterprises.