sollapalooza
Mechanical
- Feb 28, 2014
- 13
Hello
I am reviewing an old PV Elite output and noticed the following, please find my questions in red font:
However when I check section Longitudinal Allowable Stresses, something does not add up. From my understanding in UG-23(d);
For the combination of earthquake loading, or wind loading with other loadings in UG-22, the wall thickness of a vessel computed by these rules shall be determined such that the general primary membrane stress shall not exceed 1.2 times the maximum allowable stress permitted in (a), (b), or (c) above. This rule is applicable to stresses caused by internal pressure, external pressure, and axial compressive load on a cylinder.
In the Ouput
Thank you in advance
I am reviewing an old PV Elite output and noticed the following, please find my questions in red font:
Material: SA-516 Gr 60 Normalized
Allowable Stress, Ambient = 118 MPa <--- at ambient
Allowable Stress, Operating = 109.1 MPa <--- at design temperature
Allowable Stress, Hydrotest = 198 MPa <--- this 90% of Yield Strength at ambient ( 90% x 220 MPa)
Allowable Stress, Ambient = 118 MPa <--- at ambient
Allowable Stress, Operating = 109.1 MPa <--- at design temperature
Allowable Stress, Hydrotest = 198 MPa <--- this 90% of Yield Strength at ambient ( 90% x 220 MPa)
However when I check section Longitudinal Allowable Stresses, something does not add up. From my understanding in UG-23(d);
For the combination of earthquake loading, or wind loading with other loadings in UG-22, the wall thickness of a vessel computed by these rules shall be determined such that the general primary membrane stress shall not exceed 1.2 times the maximum allowable stress permitted in (a), (b), or (c) above. This rule is applicable to stresses caused by internal pressure, external pressure, and axial compressive load on a cylinder.
In the Ouput
Longitudinal Allowable Stresses
Tensile = 130.947 MPa <--- this is 1.2 x 109.1 MPa, UG-23(d)
Hydrotest Tensile = 237.596 MPa <--- this is 1.2 x 198 MPa, UG-23(d) as well but this is higher than yield strength, is this allowed? The vessel would yield past 220 MPa.
Compressive = -73.7415 MPa <--- UG-23(b), I tried to use ASME II Part D chart but cannot seem to get the same figure.
Hydrotest Compressive = -129.705 <--- How do I get this figure?
Tensile = 130.947 MPa <--- this is 1.2 x 109.1 MPa, UG-23(d)
Hydrotest Tensile = 237.596 MPa <--- this is 1.2 x 198 MPa, UG-23(d) as well but this is higher than yield strength, is this allowed? The vessel would yield past 220 MPa.
Compressive = -73.7415 MPa <--- UG-23(b), I tried to use ASME II Part D chart but cannot seem to get the same figure.
Hydrotest Compressive = -129.705 <--- How do I get this figure?
Thank you in advance