I would appreciate your advice on some issues regarding the equipment dimensions. . . . . .

Personally, I don’t think it’s necessary to be that precise; the towers I have designed and verified also don’t require such exact specifications； In terms of the processing and manufacturing of chemical engineering equipment, the errors achieved cannot reach such high levels of precision (especially for large-scale equipment). Moreover, such high precision in markings is not practically useful – is it possible to achieve such precision during on-site processing and installation? :funk:

This is a requirement from the design institute; it’s to avoid installation errors

In general design, integer values are used, with 10 centimeters serving as the standard unit of measurement. For example, EL17600.

1. The elevations in design institutes are generally accurate to the millimeter level, which is the standard practice internationally, and no one raises any objections to this. As for what was said on site that precision isn’t that important and that it’s okay to reduce it, I don’t think there’s any need for that. The dimensions must be specified accurately, including the thickness of the gasket, which is 3mm; these values need to correspond to various heights. It’s not sufficient to say it’s more or less okay. During construction, carelessness in different areas may result in a difference of a few 3mm here or there, and in such cases it might even be impossible to fit the gasket properly. Therefore, it is still necessary to maintain accuracy in dimension control. 2. The diameter of equipment is generally specified as the inner diameter. 3. The elevation of equipment is usually calculated based on ±0.000m.

The diameter of large oil refining tower equipment is generally specified as \"several hundred to several thousand\" millimeters, with most values being whole numbers; whereas the height of such equipment is usually indicated with precision down to the millimeter, and sometimes even to one decimal place beyond that. The diameter is specified as a standard nominal value, while the elevation values used in engineering are intended for construction purposes. I’m not sure if such precision is really necessary. The height of this equipment is determined at a certain ambient temperature; for devices that are several dozen meters tall, differences in temperature can result in variations of several millimeters. Is the height specification of the equipment referring to the equipment body itself (from the top flange to the bottom flange)? Does it include the skirt, head, and inlet/outlet pipes at the top and bottom? (I don’t know about these two: loveliness:) For large oil refining tower equipment, should the diameter be specified as the inner diameter or the outer diameter? When the wall thicknesses of the upper and lower sections of the equipment differ, should it be the inner diameter or the outer diameter that remains constant? For sheets rolled into shapes, the inner diameter is used; for pipes, the outer diameter is used. This post was last edited by Mo Jiruo on 2009-4-18 at 15:26.]

The equipment elevation is a relative value, representing the height with respect to the “zero” elevation. It should be measured at room temperature. As for “Is such precision necessary?” ”These values are all calculated based on the structure of the equipment and its zero elevation, so they cannot be changed arbitrarily. The actual dimensions can indeed vary by several dozen “mm”, and other equipment fittings also have their own tolerances; therefore, piping design must include a margin for adjustment.

In my opinion, there’s no need for such precision; towers are generally specified by their inner diameter, and the thickness of each section also needs to be indicated

These are two ranges! The dimensions of the device itself are of course very precise! However, in piping work, emphasis is placed on data such as the layout and length of the pipes; the more precise such information is, the better, especially for those aspects that are closely related to piping. As for those aspects that have little to do with piping, precision isn’t that important! Hehe

1. The tower height (cylinder height) is determined during the design process as calculated, and it is generally not a round number. The height of the tower skirt base can be rounded according to the layout. 2. The marking of tower height is generally carried out in accordance with the unified regulations of the design institute. 3. The tower diameter generally refers to the inner diameter.