Is it okay not to use a pipe fitting on the flange of a pressure vessel?
Thread Content
Is it okay not to use a connection flange on the equipment connection flange? Can long-neck butt-welded pipe flanges (HG/T20592-2009) be welded directly to the head? When heat preservation isn’t needed, there’s no reason to have a pipe, right?
The flange neck is very short; after welding, the flange surface is almost in contact with the head, which makes it difficult to install and remove bolts and nuts. Additionally, HG20583 specifies certain requirements regarding the extent to which the flange connections can protrude, even in the absence of insulation. What is the purpose of wanting to avoid taking over? If welding pipes is not desired, an integral long-neck flange can be used. Alternatively, a flange structure with bolt threading can also reduce the overhang height.
For flanges, the minimum specified in the standards is DN200; how should one choose for smaller openings? If checked, the thickness is also quite large. Is that overall long-neck flange also specified in HG/T20592-2009? It seems you’re quite familiar with these things; I need to learn from you properly*
The flange can be of any size, as long as the reinforcement is adequate. The flange dimensions are in accordance with the standards for pipe flanges: outer diameter, bolt hole diameter, number of bolts, and seal surface dimensions. The overall flange also conforms to the standards for pipe flanges, as specified in HG/T20592-2009, P50 (European standard) ； P283 (US standard)
The flanges need to be checked separately, right? The dimensions of the flanges are similar to those of the gaskets; it seems that there isn’t much difference between the overall gasket and the flange. Is the overall gasket simply an extended long-neck butt-welded flange? . Also, is it possible to use counterboring for the connection between the flange and the flange cover, so that no nuts are needed? (It’s just a random idea; it seems a bit odd.) . . . It feels great that so many questions come to mind as soon as I start talking to you
The applications for flanges and integral flanges are different; it’s hard to say exactly, and each case needs to be handled on its own. If one wants to avoid using a nut in a flange connection, the flange on that side must have a certain thickness – at least 1.5 times the diameter of the bolts. Standard pipe flanges do not meet this requirement (I’m not sure if this is the same issue you’re facing......)
Yes, yes, yes, you’ve explained it perfectly. . . How can one determine when to use flanges and integral flanges? The flanges I’ve seen are generally integrated with the equipment, such as those on valves; they’re not welded on