Please refer the following details.

Shell Thickness (ts)=18 mm with 10 mm CA
Wear Plate Width =250 mm.
Wear Plate Thickness(tw) =16 mm.
Saddle width (b) =230mm

Please note that as per Denis R. Moss and also from Meggasy it is clear that in formula for Circumferential Compression at Bottom of Shell, thickness of shell can be considered as combined thickness(shell thickness + Wear plate thickness) only if width of the wear plate is minimunm (b+1.56 sqrt(r.ts)).

But in pvelite it is not examining the above condition while calculating the circumferential stress at bottom of the shell.

What the pvelite is doing is putting the value of Wear Plate width (250) equal to (b+1.56 sqrt(r.ts)) and combined thickness (10+16=24) is considered that might be wrong.

My client is also not agreed on this calculation.

Please check the above case and clarify urgently.


Regards,
Satish Yadav

Dear Moderators,

Waiting for reply.


Regards,
Satish Yadav

Hello yadavsatish

For the inclusion of the wear plate, several conditions have to fulfilled. The saddle centreline has to be within R/2 of the nearest tangent line. The wear plate must have a minimum width, and the wear plate has to extend beyond the saddle either side by about 6 degrees.

In the 2010 version of PV Elite (to be released about December) we have re-written the saddle analysis to conform to the method set out the 2007 version of ASME Section VIII, Division 2.

The problem with the saddle procedure is that there are several published methods available. It is hoped that by using the Division 2 method, all the problems associated with the various interpretation are eliminated.

Ray,

We are well aware that several published methods are availabe for saddle analysis.

Please read my query above carefully and clarify, the conditions for the wear plate thickness cosideration in pvelite2009. Also provide the reference for current saddle anlysis (Specially Circumferential compression at the bottom of shell over saddle) in Pvelite 2009 so that we can tell our client accordingly.

Please note that my query is related wear plate thickness consideration perticularly in Circumferential compression at the bottom of shell over saddle.


Also it is requsted to you that please answers the queries in regards with the current version of pvelite (2009) since the 2010 version is still not available.

Regards,
Satish Yadav

Hello yadavsatish

Please send me your PV Elite file, and I shall go through it to see exactly what is happening. You can send it to techsupport@coade.com for my attention.