How to understand that the bolt holes in the flange of the head should be arranged so as to cross the alignment line passing through the center of the head and the center of the pipe"
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The flange was positioned at the mid-span many years ago; I thought I understood it then. Today, I came across this statement: “The bolt holes in the flange of the head should be arranged at the mid-point of the alignment line that passes through the center of the head and the center of the nozzle,” and it was a bit confusing to me. Is it the same as what’s correct below? Please help to clarify this. Also, for horizontal connections on horizontal vessels, is it still necessary to place the flange at the mid-span? What standards specify this?
Here’s how I understand it: Suppose the connection point is not at the center of the head; for example, if there are openings around the upper head of a reaction tank, then there is a line connecting the centerline of this connection point to the centerline of the head. The screw holes in the flange are through-holes, and this connecting line represents the midpoint – the center of that section. I’m not sure if this conveys the idea clearly; let’s discuss it together.
I want to upload a picture, but I don’t know how to do it; I’ve posted two threads. Please take a look at this post; it contains pictures. Which image does it correspond to? Right or wrong? https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1922105
This post was last edited by letitbe on 2018-2-6 at 10:36. The flange mentioned at the top actually refers to the difference between horizontal and vertical containers; the image in the \"Frequently Asked Questions\" section pertains to the flange ports of horizontal containers. In the case of vertical containers, the bolt holes need to be arranged in accordance with the direction in which the pipes extend outside the container. However, in practical engineering work, no one really pays close attention to this aspect when dealing with vertical containers”
The key point is that if the flange leaks and there are no bolts in the main direction of fluid flow, this prevents the bolts from corroding and breaking due to the flowing fluid, which could otherwise lead to an escalation of the accident.
It is necessary to distinguish whether it is the head of a bedroom container or that of a vertical device.
1 To avoid corrosion of the bolts by leaking media, the flange bolt arrangement should be at the mid-span of the gravity line. 2 When considering uniform stress on the bolts, the flange bolt arrangement should be at the mid-span in the direction of the additional lateral load on the pipeline. 3 “Arranging it at the mid-span along the alignment lines passing through the center of the head and the center of the nozzle” – I’m not sure what the advantage of this is. Perhaps for aesthetic reasons, or just to have clear, actionable rules?
In accordance with GB150-2011, the flange bolt holes should be arranged at the mid-point of the shell’s main axis or plumb line. If there are special requirements, they should be indicated on the drawing. ““The bolt holes in the flange on the head shall be arranged at the mid-point of the alignment line passing through the center of the head and the center of the nozzle” – this is a special requirement that can be specified. However, I personally believe this sentence is problematic regarding the 45-degree inclined nozzles on the heads of horizontal vessels. In this way, the bolt will be positioned on the vertical line.
Where does the statement \"The bolt holes in the flange on the head should be arranged at the mid-point of the alignment line passing through the center of the head and the center of the nozzle\" come from?