Hydraulic test stress verification
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This post was last edited by HSLJHZ on 2018-5-25 at 10:58. I would like to ask everyone: regarding the stress verification in hydraulic testing, why are the formulas used in SW6 different from those in GB/T150? It must be related to the welding joint coefficient. The stress level permitted for passing the pressure test is Ts]T￡ 0.90 ReL = 310.50
Please take a look at the formulas in the calculation sheet.
This post was last edited by zjq1962 on 2018-5-25 at 11:17. Is the author referring to Equation 3-3 in GB/T150.3? Does that mean
4.6.3 a) in GB/T150.1
The last edit to this post was made by zjq1962 on 2018-5-25 at 11:22. The joint coefficient is taken into account in the formulas used in SW6, whereas it is not included in the checking calculations according to GB150. Referring to formula 3-3 in GB/T150.3, if Pc is replaced with PT, and the coefficient is placed at the end of the checking formula, the result remains the same
This post was last edited by HSLJHZ on 2018-5-25 at 11:32. Isn’t the weld joint factor already taken into account in GB/T150.1 4.6.3 a) σT≤0.90 ReL φ?
The last edit to this post was made by zjq1962 on 2018-5-25 at 14:00. SW6 takes the joint coefficient φ into account in its stress calculation formulas; therefore, φ is not included in the verification formulas. GB/T150 does not consider the joint coefficient φ in its formula calculations, so φ is included in the verification formulas. By simply replacing Pc in the stress calculation formula of GB/T150 with PT, one obtains the stress calculation formula for pressure testing; when performing verification, the allowable stress should be replaced with the yield strength.
Essentially, a pressure test is a process of stress enhancement; therefore, the controlled value for the test pressure should not exceed 0.9 times the yield strength at room temperature