FPPE
Mechanical
- Mar 4, 2022
- 196
Dears,
I would like to know how do you order raw forging in order to perform the following weld overlay on heat exchanger tubesheets.
Typically, we order the raw forging with the conical surface in the side where the weld overlay is to be performed, where the height of the conical section depends on the diameter, thickness, and base material and weld overlay material (can vary from 3 to 15 mm in our cases).
By doing so, once the weld overlay that causes the tubesheet to flex has been performed, if the height of the conical section has been chosen correctly, the plate will bend and the conical surface will become flat (due to the thermal stresses caused by the weld overlay), and on the other side, a convexity will be obtained, which will be machined later to obtain a flat surface.
If all the procedure is correct, you will get a tubesheet with the thicknesses along the entire radius corresponding to the design, with a constant weld overlay thickness, and with the thickness of the base material at the center equal to that calculated, and not less.
The problem is that it happens to be wrong, because the height of the cone is decided on the basis of experience. So I would like to understand what steps you use to perform a weld overlay on tubesheets, whether it is ordering raw forging with a certain geometry or any other expedient to keep the tubesheet from deforming.
Thank you in advance!
I would like to know how do you order raw forging in order to perform the following weld overlay on heat exchanger tubesheets.
Typically, we order the raw forging with the conical surface in the side where the weld overlay is to be performed, where the height of the conical section depends on the diameter, thickness, and base material and weld overlay material (can vary from 3 to 15 mm in our cases).
By doing so, once the weld overlay that causes the tubesheet to flex has been performed, if the height of the conical section has been chosen correctly, the plate will bend and the conical surface will become flat (due to the thermal stresses caused by the weld overlay), and on the other side, a convexity will be obtained, which will be machined later to obtain a flat surface.
If all the procedure is correct, you will get a tubesheet with the thicknesses along the entire radius corresponding to the design, with a constant weld overlay thickness, and with the thickness of the base material at the center equal to that calculated, and not less.
The problem is that it happens to be wrong, because the height of the cone is decided on the basis of experience. So I would like to understand what steps you use to perform a weld overlay on tubesheets, whether it is ordering raw forging with a certain geometry or any other expedient to keep the tubesheet from deforming.
Thank you in advance!