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ASME VIII 1943 Sections U-68 and U-69 1
- Thread starter Rubje
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Christine74
Mechanical
The U-1 Data Report should list the joint efficiency on Line 8. If you don't have a U-1 it's possible that the joint efficiency was listed somewhere on the original drawing, or if the MAWP was listed it may be possible to back-calculate the joint efficiency.
Otherwise if you have documentation to back up that all of testing outlined in U-68 was performed, the efficiency E = 0.90. Otherwise, E = 0.80 as long as the requirements of U-69 are met.
-Christine
Otherwise if you have documentation to back up that all of testing outlined in U-68 was performed, the efficiency E = 0.90. Otherwise, E = 0.80 as long as the requirements of U-69 are met.
-Christine
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- #3
@Christine74
Thank you for the guidance.
Do you know why the joint efficiencies were relatively high in the 40s but were lowered starting in the 50s?
I find that concerning because many of these old vessels were built with very little corrosion allowance so if today's joint efficiencies were applied to these 1940s vessels they would most likely be below Tmin.
Thank you for the guidance.
Do you know why the joint efficiencies were relatively high in the 40s but were lowered starting in the 50s?
I find that concerning because many of these old vessels were built with very little corrosion allowance so if today's joint efficiencies were applied to these 1940s vessels they would most likely be below Tmin.
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- #5
@weldstan
True and rightfully so due to the technology back then
However, the S.F. was increased to 4 temporarily due to WWII in the early 40s to save metal for the military. Is it safe to assume that any vessel built during this time period should be heavily questioned if they are still in operation today?
True and rightfully so due to the technology back then
However, the S.F. was increased to 4 temporarily due to WWII in the early 40s to save metal for the military. Is it safe to assume that any vessel built during this time period should be heavily questioned if they are still in operation today?
Christine74
Mechanical
The 4:1 design margin in the API-ASME Code was first introduced in 1934 so it pre-dates WWII. If I remember correctly ASME Section VIII maintained a 5:1 design margin until 1950.
Many such vessels have been in continuous operation since that era without any problems.
-Christine
Many such vessels have been in continuous operation since that era without any problems.
-Christine
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Christine74
Mechanical
Some information about the history of the API-ASME code is discussed the Forward of earlier editions of API 510:
"In December 1931, API and the American Society of Mechanical Engineers (ASME) created the Joint APIIASME Committee on Unfired Pressure Vessels. This committee was created to formulate and prepare for publication a code for safe practices in the design, construction, inspection, and repair of pressure vessels to be used in the petroleum industry. Entitled APIIASME Code for Unfired Pressure Vessels for Petroleum Liquids and Gases (commonly called the API/ASME Code for Unfired Pressure Vessels or API/ASME Code), the first edition of the code was approved for publication in 1934."
-Christine
"In December 1931, API and the American Society of Mechanical Engineers (ASME) created the Joint APIIASME Committee on Unfired Pressure Vessels. This committee was created to formulate and prepare for publication a code for safe practices in the design, construction, inspection, and repair of pressure vessels to be used in the petroleum industry. Entitled APIIASME Code for Unfired Pressure Vessels for Petroleum Liquids and Gases (commonly called the API/ASME Code for Unfired Pressure Vessels or API/ASME Code), the first edition of the code was approved for publication in 1934."
-Christine
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