Can necked butt-weld flanges and integral flanges be connected in pairs?
Thread Content
Can necked butt-weld flanges WN and integral flanges IF be connected to each other? From the diagram, it seems that the inner diameters of the flanges don’t match – one is 19 and the other is 21. Is it possible to connect them together? They are all convex, rf.
Check the outer diameter, hole spacing, hole size, and sealing surface
First, the necked butt-weld flange is also an integral flange, and an integral flange is used in contrast to a loose flange. Second, why not match them together using the same model? Firstly, there may be deviations in the position of the bolt holes. Under conditions of pre-tensioning or operation, the bolts may have to bear excessive bending stresses resulting from bending moments; such additional bending stresses are not taken into account in the design loads for the bolts, and they can accelerate their failure.
As long as the sealing surfaces, the number of threaded holes, and the pitch radius of the threaded holes are all the same, then connection is possible; it has nothing to do with the inner diameter. The inner diameter is related to the wall thickness of the connected pipeline; in principle, the wall thickness at the flange joint should be the same as that of the pipeline.
The first one is fine; it indeed belongs to the integral flange type. But in my view, WN involves welding the flange neck to the steel pipe, while IS is an integral forged piece, right?
This post was last edited by wanlirn on 2019-5-10 15:26. Are you being deliberately ignorant? Haven’t you seen pipes, valves, or pumps connected? The inlets and outlets of valves or pumps are designed with integral flanges.
What an expert; even for the issue of connecting a pipe flange to a valve or pump flange, they developed an entire theory
First, I’m no genius. Second, it is a type of integral flange with a neck; please refer to GB150 for details. Third, please pay attention to my message. By deviation in the bolt hole positions, I mean that the bolt holes of the two flanges do not align with each other; in such a case, if they are assembled together. The bolt is loaded at an angle.