Seamless steel pipe formula calculation method

Method One:

Seamless steel pipe pressure calculation method , seamless steel tubes,alloy steel seamless and welded steel pipe subjected to internal pressure, total wall thickness is calculated according to the following formula:

The PD  δ =------+ C       200 [σ] φ + P (2-1)

Wherein d a - tube Pik Thickness (mm); 
　　P - pipe the inner dielectric workers ashamed pressure (kg / cm 2 ); when the pressure is not high, the P value of the denominator in the formula desirable P = 0, in order to simplify calculation; 
　　the D- - outside diameter of pipe (mm); 
　　φ - weld coefficient, Seamless pipe φ = 1, straight seam welded steel pipe φ = 0.8, spiral seam welding Steel Pipe φ = 0.6; 
　　[σ] - allowable stress of the pipe (kg 　　C - tube wall thickness / mm 2 ), pipe stress value allowable under various temperature are shown in Table 2-5; 
additional amount (mm). 
　　Tube wall thickness additional amount determined as follows:

C = C1 + of C2 + C3  (2-2)

 

Method:

The tube can withstand the pressure P = (2 * σ / S * δ) / D wherein: the pressure is P, the tensile strength of σ, S is a safety factor, the wall thickness of δ, the pipe diameter D. Let the tensile strength of the material is σ, the pressure P, the pipe diameter D; pipe wall thickness δ = (p * D) / (2 * σ / S)wherein S is the safety factor; because P is less than 7MPa, S election S = 8; P less than 17.5MPa, the S select S = 6; P greater than 17.5MPa, S select S = 4; we selected safety factor of S = 6; select the tensile strength of the steel 20 to 410 MPa, so the tube can withstand the pressure P = (2 * σ / S * δ) / D                    = (2 * 410/6 * 3) / (10 +6)                    = 26.25MPa>, setting 17.5MPa therefore safety factor of S = 4 Therefore, the tube can withstand the pressure P = (2 * σ / S * δ) / D