45 degree bevel of tail pipe
45 degree bevel of tail pipe
(OP)
What are the advantages and/or disadvantages in applying a 45 degree bevel at the end of the tail pipe of a safety valve? I am thinking about forces, noise,...
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45 degree bevel of tail pipe
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RE: 45 degree bevel of tail pipe
Thanks!
Pete
RE: 45 degree bevel of tail pipe
RE: 45 degree bevel of tail pipe
I was always under the impression that the larger opening of the bevelled end was to minimize the velocity of the discharging steam (or whatever fluid is being handled).
If nothing else, it's the mark of a proper fitting job - that attention was paid to detail. It's like walking into a boiler room. At least 99% of the time, your first impression tells the tale. If it's a nice, clean plant, and looks like it's been taken care of properly, it likely is, in all respects. If it looks like a dirty junk-hole, it likely is, again, in all respects.
RE: 45 degree bevel of tail pipe
As TBP states, it's mostly for "looks" and aesthetics. It probably looks more "engineered" to some people - when it really isn't. The beveled cut does not reduce the exit velocity any more than a 90 degree cut - both have the same effect and there is no difference in the results. Proof of this is that the type of cut NEVER enters into any PSV discharge calculations.
Additionally, if rain drops are falling perpendicularly (as they often do), the exposed open area is the same when the tail pipe is pointing directly up. Therefore, a beveled nozzle will not collect more rain water - and even if it did, the PSV outlet should have a drain hole in the bottom horizontal section anyway and water collection should not be a problem. So, in the end, the only advantage is "Looks".
Art Montemayor
Spring, TX
RE: 45 degree bevel of tail pipe
RE: 45 degree bevel of tail pipe
I'm afraid the cross-sectional area of the pipe that the rain sees, when the pipe is vertically straight up, is nothing more than a perfect circle - regardless of what angle the pipe nozzle is cut at. If you can visualize the vertical view of the nozzle, rotate it 90 degrees and obtain the "plan" view of the vertical nozzle (or a "bird's eye view") and you will see that the vertical, falling rain sees only a perfect circle - the same as if the nozzle were cut square. The rain does not "see" an oval or a cross-section other than that of a circle.
Art Montemayor
Spring, TX
RE: 45 degree bevel of tail pipe
RE: 45 degree bevel of tail pipe
RE: 45 degree bevel of tail pipe