Why are the studs of DN40 longer than those of DN50?
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This post was last edited by the-end on 2011-5-22 at 16:50. While working on the material table today, I suddenly noticed this issue: in HG20634, for the 300LB studs, it can be seen that the studs selected for DN40 have both a higher number of threads and a greater length compared to those used for DN50. The same is true for 600LB studs. What could be the reason for this, everyone?
There is a length requirement for the connection, right? Isn’t the bolt M40?
The bolt specifications for the DN40, CL300 flanges are M20X100X4 sets, while those for the DN50, CL600 flanges are M16X115X8 sets. Since the number of bolt holes in the flanges of these two types is different, the bolt specifications also differ.
The number of flange bolt holes is different in the two, so of course there are differences! :)
I checked HG20634: for PN2.0 (300LB) and DN40 and DN50, the number of bolts is 4, with specifications of M14×85 and M16×95 respectively. At PN5.0 (600LB), the number of bolts for DN40 and DN50 is 4 and 8 respectively, with specifications of M20×110 and M16×105 respectively. With a large number of bolts, finer attention is certainly needed.
HG/T20634-2009: DN40 – M20×100×4; DN50 – M16×95×8. The studs are shorter because the number of bolt holes has increased, which enables achieving the desired level of tightening
Well, it drops a bit; at 150LB, both DN40 and DN50 have four studs. At 300LB and 600LB, the number of studs changes exactly at the boundary between DN40 and DN50