Why can’t thick plates be directly processed for use as thin plates?

I’ve never seen the wall thickness of containers expressed as a decimal value; it is usually rounded off. For a plate of a certain thickness, the wall thickness is rounded to the nearest whole number. For example, if the thickness is 4.78 mm, it is typically rounded to 6 mm rather than 5 mm, as plates with odd thicknesses are not common – thicknesses are usually even

Thickness can be used in place of thinness on the container! When it is feasible, direct substitution is possible; then why go through the hassle of processing, thinning, or stretching? Most manufacturers simply use direct substitution

There’s no need to make thick ones thinner – can’t thick designs be used? When I was making acid tanks, I didn’t have the desired size, so I chose thick ones, and they worked just fine

This is a type of connector that requires connection to an external site. The dimensions of the external connector are OD406.4 X 4.78; it’s a standard pipe. However, as a manufacturer, it’s not possible to purchase such pipes in large quantities – only 200 mm long pieces are available. Therefore, the pipes have to be bent into shape manually. This, however, leads to issues with inconsistencies in the port sizes.

It’s sufficient to machine a bevel at the port according to OD406.4 X 4,78.

It’s better not to do that; just use a substitute. There are many ways to join thick pipes with thin pipes, and all of them are better than thinning out the thick pipe

I guess the dimensions on the original device’s drawings were converted from inches, which is why there are decimals, haha.

The original poster is mistaken; an outer diameter of 406.4 mm and a wall thickness of 4.78 mm correspond to the ASME pipe fitting standards, and these are seamless pipes. They can be substituted using sheet metal first, taking into account the thickness difference when connecting with long-neck flanges. The flow velocity between the pipes does not change much; under normal circumstances, as long as the material quality is satisfactory and 100% non-destructive testing is passed, such substitution is feasible.

The dimensions of the external fitting are OD406.4 X 4,78; it is a standard pipe. As a manufacturer, it is not possible to purchase such a pipe, but one can use shorter pipes with the same inner diameter. In the case of butt welding, it is required that the inner walls of the pipes be aligned properly; if there is a misalignment, the local deviation for single-sided welding should not exceed 10% of the wall thickness and should not be more than 1 mm. For flange connections, simply use the inner diameter of the flange.

OD406.4 X 4.78 corresponds to the imperial specification NPS16 SCH 10S; it is usually a welded pipe used in low-pressure or atmospheric pressure applications. Connection to external pipes can only be achieved through single-sided welding on the outside side; therefore, the inner walls need to be aligned, but the outer walls do not necessarily have to be aligned. Therefore, 6mm plate rolling welding is used to control the perimeter of the inner wall in order to regulate the misalignment amount when assembling with external pipes, while also controlling the ellipticity of the shape; the specific criteria depend on the equipment’s manufacturing acceptance standards. The outer wall thickness is 1–2 mm; there is no need for machining to thin it. Due to the ellipticity and thin wall thickness, it is actually not very easy to machine as well. As for the claim that “thick plates cannot be directly processed for use as thin plates,” there isn’t any such thing, I think. The difference in strength resulting from varying thicknesses of steel plates of the same grade may need to be taken into account; for example, Q345R steel plates with thicknesses of 16 mm and 18 mm differ in yield strength by 20 MPa.