Please let me preface this post by saying that my company has not yet upgraded to PV Elite 2011, so I am unaware if this issue has already been resolved.

I am attempting to perform Appendix 1-10 calculations for a nozzle in a conical shell oriented perpendicular to the longitudinal axis as described in fig. 1-10-6 of App. 1-10. I agree with all of the calculations that PV Elite performs except for the determination of the effective radius, Rnc.

PV Elite 2010 states that for non-radial nozzles in cones, Rnc is calculated as follows:

Effective Radius for non-radial Nozzles in Cones [Rnc]:

= Rn / sin( theta )

= 29.468 / sin( 90.000 )

= 51.348 in.

Clearly the calculation above does not add up, but I also believe it is not using the correct equation from App. 1-10. The guidance that I see in App. 1-10 for such a nozzle is:

Rnc = Rn / cos(alpha)

I am missing something? Can someone please shed some light on this issue?

Hello mdsimon2

Consider a cone.

Consider a nozzle perpendicular to the longitudianl axis of cone.

So the angle between the 2 centerlines comes to be 90 deg.

now to know the effective opening radius of nozzle in cone shell we go by following steps.

1) calculate cone half apex angle
2) calculate nozzle inside radius.
3) divide step 2 by cosine of step 1.
4) you will get effective nozzle opening radius in cone.

now PVElite 2011 considers centerlineS angle between cone and nozzle and use it to calculate effective nozzle opening radius.

Also it uses the formula Rnc = Rn / sin( theta )

I think there is a problem considering the angle to be used in the calculation of effective nozzle opening radius.

Opininons are most welcome.

Hope this helps.
Regards
ASD23789

It has been a while since my original post, but I recently ran into another situation where I need to perform Appendix 1-10 calculations on a nozzle in a conical shell oriented perpendicular to the longitudinal axis of the conical shell.

I agree with the procedure proposed by asd23789 (equivalent to Rnc = Rn/cos(alpha) expression I original posted) for calculating effective nozzle opening radius.

I have created a mathcad worksheet to perform Appendix 1-10 calculations in lieu of using PV Elite, but I would like to know if Intergraph has any insight into this error? Is this a known issue with PV Elite 2010?

Hi All,

PV Elite version 2010 and prior versions were using the outer nozzle radius as depicted in Figure 1-10-6 to determine the value of Rnc which led to a conservative (lower) MAWP for the opening. The text in the equation substitution was also incorrectly displayed. It should have been cos(alpha) and not sin(theta). The internal equation was correctly using cos(alpha).

PV Elite version 2012 ( late November 2012 ) will correct this issue.