Large opening under negative pressure on elliptical head
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This post was last edited by ylx0611 on 2012-3-4 at 10:52. I would like to ask the experts: It’s a heat exchange unit with a pressure of 0.8 MPa on the shell side and -0.1 MPa on the tube side; the diameter is 2000 mm, and there is a hole of 1400 mm in size in the tube-side head. This value exceeds the limits specified in GB150, as well as the limit of di/D ≤ 0.6 outlined in HG20582. Could someone please tell me how to carry out the calculations? Thank you. If anyone has the calculation results, I would appreciate it if they could share them with me for reference. Thanks! ! Urgent! ! !
Out of range: calculate using the stress analysis method, or employ the pressure area stress method specified in ASME 8-2; for the specific calculation procedures, refer to ASME 8-2
Original poster, you don’t need to create holes; you can use a flanged cone-shaped end cap and connect it with pipe flanges. Why go through the trouble of installing an end cap only to remove it later, leaving behind that poor-quality transition area? ? ?
Thank you all. The suggestion from above is good; we can discuss it with the property owner!
This post was last edited by ylx0611 on 2012-3-10 at 15:06. I just used the cone-sealing method to check it, and it worked; thanks to everyone. I wanted to give everyone some extra points, but after trying several times I kept getting the message that the entered score was incorrect. I tried all values from +1 to +5, with no success. Is it because our level is too low that we can’t give others points?
There are many advantages to conical end caps. First, they can serve as a transition section. It should be noted that according to GB151, a anti-erosion plate is required at the inlet of the tube side in heat exchangers of this type, but is it really necessary? If it is added, the flow area will decrease, which will lead to new erosion. Therefore, using a conical seal can effectively increase the buffer length, and the cost is not high – after all, conical seals are relatively easy to manufacture. With such low pressure, a seamless conical seal can also be used directly. Secondly, it is to avoid the situation where a head is fabricated only for to have the area under the most stress in that head removed, which results in waste of material and money.