Stonecold
2008-11-06 02:19:01
3
393
Whenever we are doing manifold design, do we have to consider ligament efficiency even though number of holes are two or three and hole pitch is more than 5 times pitch?
Is there any requirement to consider ligament efficiency in ASME?
Is there any requirement to consider ligament efficiency in ASME?
Thank you for your reply.
I also failed to find any ligament regulation for manifold.
However client insist to check the manifold thickness together with the ligament condition based on the following sectence which is on ASME Sec.VIII-D1, UG-27
"E : joint efficiency for, or the efficiency of, appropriate joint in cylindrical or spherical shells, or the efficiency of ligaments between openings, whichever is less.
For welded vessels, use the efficiency specified
in UW-12.
For ligaments between openings, use the efficiency
calculated by the rules given in UG-53."
I think that the ligament mentioned above above is applied for the pipe or plate taht have more that two rows and many holes.
Our manifold has only two branches and the pitch is more that five times diameter.
Is there any way to persuade the client?
If we consider the ligament, manifold thickness should be thicker.
I also failed to find any ligament regulation for manifold.
However client insist to check the manifold thickness together with the ligament condition based on the following sectence which is on ASME Sec.VIII-D1, UG-27
"E : joint efficiency for, or the efficiency of, appropriate joint in cylindrical or spherical shells, or the efficiency of ligaments between openings, whichever is less.
For welded vessels, use the efficiency specified
in UW-12.
For ligaments between openings, use the efficiency
calculated by the rules given in UG-53."
I think that the ligament mentioned above above is applied for the pipe or plate taht have more that two rows and many holes.
Our manifold has only two branches and the pitch is more that five times diameter.
Is there any way to persuade the client?
If we consider the ligament, manifold thickness should be thicker.
공지사항
However you can find the requirements of ASME Sec. VIII-D1, UG-53 when you apply to pressure vessel code.