Non-standard elliptical head
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Approximate dimensions of the elliptical head: the long axis is 488 mm and the short axis is 256 mm. My questions are: 1. What is the radius at the corner area? 2. What is the spherical radius? This post was last edited by HMQ184 on 2009-3-13 12:54.]
Why not choose the standard one? If that doesn’t work, go with a butterfly head; I don’t know which standard specifies the radius for that
Some conditions of the drawing are determined by the user; there’s nothing I can do about it
It can be drawn using the method for drawing an ellipse. With a major axis of 488 mm and a minor axis of 256 mm, the following results are obtained: 1. The radius of the turning zone is: 90.1 mm. 2. The radius of the sphere is: 421.4 mm
It is included in JB/T4746
There isn’t actually any, but the inspector at that time insisted that I mark it; if drawn using a simplified ellipse representation, there would be two R values. In reality, there is none in CAD drawings, and inspectors with higher expertise have confirmed this
Finally, the standard head specification JB/T4726 is used as a reference, as the stresses acting on the head are quite complex
If manufacturing is considered, it’s sufficient to create a mold that meets the requirements. As for calculating the stress and wall thickness, since it is only 6 mm deeper than the standard 2:1 ellipse, it is recommended to use the standards for ellipse calculations, which will suffice
Gentlemen, don’t confuse the concepts: elliptical heads and disc heads. Anything drawn using R represents a disc-shaped head; an ellipse cannot be represented by R – only its major axis and minor axis can be used! For the poster’s question, it is sufficient to provide the values of the major axis and minor semi-axis; use CAD to create a drawing at a 1:1 scale, and then hand it over to the manufacturing staff. As for how to manufacture it, that’s another challenge, but as long as one is willing to spend money, it’s definitely possible to create it oneself! ! The above discussion is completely unnecessary; that property owner must be an ignorant and arrogant new rich who wants to make him spend more money and extend the construction timeline – let him suffer! ! ! !
Yes, it’s really tough when dealing with owners whose technical skills aren’t advanced enough to grasp things thoroughly. My client insisted on using oval end caps and refused to use butterfly types, even though our pressure is less than 0.1 MPa(g).