Bibliography: Petrochemical Pipeline Design, P392, edited by Cai Erfu, according to the formulaλ=RyS/rp2,λIs the size factor;Ry is the effective bending radius of the bend, cm;S is the wall thickness of the bend, cm;Rp is the average wall thickness of the elbow section, cm
Bibliography: Petrochemical Pipeline Design, edited by Cai Erfu P392, according to Markl formula K=1.52/λ5/6,λIs the elbow size coefficient;K is the flexibility coefficient
According to Clark and Reissner formula, K=1.65/λIn the calculation formula,λIs the elbow size coefficient;K is the flexibility coefficient, applicable range is 0.02 ≤λ≤1.65；λ＞K=1.0 at 1.65
Bibliography: Petrochemical Pipeline Design, P392, edited by Cai Erfu, according to the formulaμ=ε'/εCalculate where,μIs Poisson's ratio;ε'Is the transverse strain, mm;εIs the axial strain, mm
Bibliography: Petrochemical Pipeline Design, P392, edited by Cai Erfu, is calculated according to the formula Et=Eo, where Eo is the elastic modulus at room temperature, MPa;T is the temperature, ℃;Et is the elastic modulus at t ℃, MPa
Bibliography: Petrochemical Pipeline Design P391, edited by Cai Erfu, is calculated according to the formula f=5.89/N0.2, where N is the number of equivalent cycles within the expected service life;F is the reduction factor of allowable stress range of pipeline
Bibliography: Pipeline Design for Petrochemical Industry P390, edited by Cai Erfu, is calculated according to the formula Sa=1.25Sc+0.25Sh, where Sa is the allowable stress range of pipeline, MPa;Sc is the allowable stress value of the pipeline at the installation temperature (cold state), MPa;Sh is the allowable stress value of the pipeline at the installation temperature (hot state), MPa
Calculate according to the formula SL=(iiMi2+ioMo2) 0.5/Z, where SL is the axial stress caused by bending moment, MPa;Mi is the bending moment of the pipe section in the plane (the plane where the elbow axis is located), N · mm;Mo is the bending moment of the pipe section outside the plane (the plane perpendicular to the above plane), N · mm;Ii is that the pipe section in the plane shall
Bibliography: Petrochemical Pipeline Design, P388, edited by Cai Erfu, is calculated according to the formula SL=(Mi2+Mo2) 0.5/Z, where SL is the axial stress caused by bending moment, MPa;Mi is the bending moment of the pipe section in the plane (the plane where the elbow axis is located), N · mm;Mo is that the pipe section is out of plane (perpendicular to the above plane
Bibliography: Petrochemical Pipeline Design, P387, edited by Cai Erfu, is calculated according to the formula SE=S1-S2=(Sb2+4St2) 0.5, where SE is the secondary stress, MPa;Sb is the axial stress generated by the bending moment caused by temperature change, MPa;St is the shear force generated by torque caused by temperature change, MPa
Bibliography: Petrochemical Pipeline Design, edited by Cai Erfu, P387 The axial stress of pipeline is mainly caused by the axial stress generated by internal or external pressure, the axial stress generated by the friction force of movable support, the axial stress on the pipeline caused by the force and moment generated by the pipe's dead weight and thermal expansion, and other forces and moments
