SnTMan,
I think I made a big big mistake saying "balanced reinforcement" when it is not really defined. Client now says he wants dollar plates because that is what I "meant". (14 nozzles). Hard to argue the point with them...
Is there a proper definition of what 'balanced' nozzle reinforcement means? I wrote it into my spec, thinking it was understood , but it is not a term used in BPVC and my client seems to think it means a dollar plate. Client does not accept my interpretation.
Thank You metengr. I should have said that I was aware of your points 1 and 2 (why didn't I say that in the OP????). I did NOT know that they contribute to SCC and corrosion fatigue. I have seen RTs that show very good correlation with the actual weld, when macroed (see OP). Under what...
Yes, before you ask: I HAVE searched this subject on Eng-Tips.
For the last couple of decades I have worked in an industry that prohibits the use of backing strips in Pressure Vessels. Why?
OK, I know what backing strips are for, and when they are appropriate, but I do not understand why there...
Thank You r6155,
Well, as I said in my original query: 'Theory and Design of Pressure Vessels' by Harvey did discuss the theory behind sleeve washers. I have only hazy recollections, but can categorically state that it had nothing to do with impact loads.
I fail to see how "sudden impact...
Yeah, that is why I followed that paragraph with:
"HOWEVER, with uninsulated bolts ..."
I accept what you say about the transient conditions, which are sort of covered in U-2 and UG-22 of BPVC.
Thank you r6155,
I wrongly referred to 'sleeve nuts': what I meant was 'sleeve washers' which are not internally threaded - they are simply plain pipe with ends machined parallel to each other, as described by Harvey (mentioned above) and EAD Saunders in 'Heat Exchangers: Selection Design and...
You first said that:
(I) "the thickness of 2:1 semi-elliptical heads are explicitly calculated using the 90-17 torispherical head approximation" [i.e., empirical]
and yet later you say that:
(II) "the design rules are most certainly not empirical, but quote rigorously scientific [ ... ?]...
Have you ever checked any of your 2:1 semi-elliptical heads with a template to see whether or not they are true semi-elliptical heads or if they are equivalent 90-17 torispherical heads?
YES, and Code tolerances apply.
I will also refer you VIII-2 4.3.6 and 4.3.7, whereby the thickness of 2:1...
Excellent! Many Thanks!
I wanted a way to get a sleeve washer to equal Bellevilles, but came up with three different answers (depending on parameters). Your answer appears to work. Thanks again!
T.E heads?
I've been working in pressure vessels since '86 and never built, bought or specified a T.E head. Ever.
Back in the 1950s when vessels were designed on a slide-rule, T.E heads made some sense.
Why?
Well, stresses in spheres and toroids were very well understood at the time...
I have been wracking my brains over the theory behind sleeve bolts (some people call these compensators).
It is a sleeve to extend the stud for high temperature service.
Every time I try to do the theory I seem to come up with a different answer. Example: one time I try to maintain constant...
Jciws.
... But that is the whole point to DBR isn't it? ASME can' t just build cost in on a whim, without some concrete justification, otherwise it will lose credibility. Mind you, I consider new div 2 to be the new go to code in the coming years.
TGS4: this is just the sort of debate I wanted to provoke. Thanks for your reply. Personally, I do feel that there are some things that are creeping into Code that are unnecessary, and this is one. Pads are not connected to shell except at the edge and at the nozzle throat, so ASME never gave...
I see some nit-wit has effectively added the ABSA IB05-004 joint efficiencies into the A5 calc in Division 1. Thankfully, this has not been done in Division 2 (AFAIK): probably because those Div2 people understand PV engineering - and know that the old rules (no JE) worked. Hopefully UG-37h...
API 661 had, some time ago, a clause to the effect that fans had to be designed such that, by increasing fan blade angle, a 10% increase in air flow can be achieved. Some of the major operators understood this to mean "and thus the motor must be sized for this increased airflow". Often, in specs...
There are a number of threads in this forum ( thread338-159732 , thread338-171512 , and thread338-130588 ) where the same contributor consistently states 'with authority' that a corrosion allowance is not required if you don't expect uniform corrosion.
Now then, as a vessel engineer in oil and...
Because that is the project requirement, of course! In an EPC contract the contractual documents are frozen at an agreed date, for purely practical reasons. Since this project was sanctioned about a couple of years ago, some of the documents are not bang up to date. That cannot be helped...
