Topic Options
#15482 - 01/23/08 10:44 PM WRC 107 and WRC 297 Limitations
Farid Masood Offline
Member

Registered: 01/23/08
Posts: 64
Loc: Pakistan Lahore
I have been studying WRC 107 and WRC 297 from various sources there is some confusion in my mind regarding their limitations.

Based on latest Revisions of WRC Bulletin 107 and 297. what are their Limitations in terms of the following parameters.
1) D/d
2) D/T
3) d/t
4) T/t
5) R/t (for WRC 107 only when we are considering a spherical portion)
6) R/d (for WRC 107 only when we are considering a spherical portion)
8) Thickness of spherical portion/t (for WRC 107 only)

where "D" is shell outside diameter, "d" is nozzle outside diameter, "T" thickness of the shell, "t" Nozzle Thickness. "R" Radius of the spherical portion for WRC 107 only, considering a HEAD.

I will really appreciate if some of you just share some information in this regard.
_________________________
*************
Farid Masood
Static Equipment Design Engineer
---------------------------------

Top
#15488 - 01/24/08 04:02 AM Re: WRC 107 and WRC 297 Limitations [Re: Farid Masood]
Stan McKay Offline
Member

Registered: 10/21/04
Posts: 102
Loc: UK
_________________________
----------
Stan McKay

Top
#15489 - 01/24/08 04:23 AM Re: WRC 107 and WRC 297 Limitations [Re: Stan McKay]
Farid Masood Offline
Member

Registered: 01/23/08
Posts: 64
Loc: Pakistan Lahore
Thanks Stan, but all these stuff does not explain all my parameters explicitly.
i have been through stuff like that but they do not cover all above. some parameters that i have written above, may need no consideration, I don,t know for sure.
further more as per the atricle published in Jun 97 news paper where it written that DN/TV (vessel dia to thickness ratio)should be greater than 50. I have done one sample calculation on PV-elite with vessel dia 1000 mm and thickness 50 mm for which the ratio is 20, but codecalc did,t give a warning.I hope you have understood my confusion.

I will appreciate your comments in this regard.

Thanks
_________________________
*************
Farid Masood
Static Equipment Design Engineer
---------------------------------

Top
#15490 - 01/24/08 04:34 AM Re: WRC 107 and WRC 297 Limitations [Re: Farid Masood]
Farid Masood Offline
Member

Registered: 01/23/08
Posts: 64
Loc: Pakistan Lahore


Further more adding to all above. I have collected below information on one of the threads that you have just mentioned.
below information reveals that for WRC d/D < 0.33 but if we refer to codeCal it says that it should be greater than .0571 and less than 0.571.
this makes confusion. if CodeCal is correct than for me the rest of the information provided below becomes absoulutely doubtful.
May be the man has referred to previous version of WRC 107 1965. but still
the doubt is there.
I hope you would not mind this.
--------------------------------------------------------
WRC 297
a) d/D <= 0.5
b) D/T<=2500
c) d/t <=100
d) Calculates vessel stress and nozzle stress
e) Used for cylindrical nozzle on cylindrical vessel

WRC 107
a) d/D < 0.33
b) Dm/T>50, where Dm = D T, mean vessel dia.
c) Calculates vessel stress only.
_________________________
Manoj Sarkar
-------------------------------------------------------------------
_________________________
*************
Farid Masood
Static Equipment Design Engineer
---------------------------------

Top
#15491 - 01/24/08 04:36 AM Re: WRC 107 and WRC 297 Limitations [Re: Stan McKay]
Farid Masood Offline
Member

Registered: 01/23/08
Posts: 64
Loc: Pakistan Lahore
Further more adding to all above. I have collected below information on one of the threads that you have just mentioned.
below information reveals that for WRC d/D < 0.33 but if we refer to codeCal it says that it should be greater than .0571 and less than 0.571.
this makes confusion. if CodeCal is correct than for me the rest of the information provided below becomes absoulutely doubtful.
May be the man has referred to previous version of WRC 107 1965. but still
the doubt is there.
I hope you would not mind this.
--------------------------------------------------------
WRC 297
a) d/D <= 0.5
b) D/T<=2500
c) d/t <=100
d) Calculates vessel stress and nozzle stress
e) Used for cylindrical nozzle on cylindrical vessel

WRC 107
a) d/D < 0.33
b) Dm/T>50, where Dm = D T, mean vessel dia.
c) Calculates vessel stress only.
_________________________
Manoj Sarkar
-------------------------------------------------------------------
_________________________
*************
Farid Mahsud
Static Equipment Design Engineer
---------------------------------

_________________________
*************
Farid Masood
Static Equipment Design Engineer
---------------------------------

Top
#15493 - 01/24/08 05:59 AM Re: WRC 107 and WRC 297 Limitations [Re: Farid Masood]
Stan McKay Offline
Member

Registered: 10/21/04
Posts: 102
Loc: UK
Farid,

The answer, unfortunately, is not explicit. All of the original work that was carried out and referenced within the WRC bulletins came from a discrete number of tests. The results of these tests were used to produce an analytical method. This method will be applicable for geometries similar to the original test pieces but cannot cover all shapes and sizes. You want to know whether your geometry will give you good results? If you look at all of the limitations published in these bulletins (check WRC107 Appendix A) and compare with your own geometry and calculated stresses you will get a better idea whether you can rely on the results you have. If your maximum stress intensity is 95% of the allowable and your geometry is on or past the recommended limits then you would do well to use another method to substantiate your design.

(Added) The differences you note in your last post are the differences between WRC107 & 297. Contained within the links given earlier are discussions about the differences between both bulletins. WRC 297 extended the work done in 107 which is why the geometrical ratios have increased. WRC107 did not take into account nozzle stresses but 297 does. If you are unsure of which one to use, use both. If you are unsure of the results, compare with another method (Annex G PD5500). If you are still uncertain, use FEA.


Edited by Stan McKay (01/24/08 06:15 AM)
_________________________
----------
Stan McKay

Top



Who's Online
0 registered (), 124 Guests and 0 Spiders online.
Key: Admin, Global Mod, Mod
May
Su M Tu W Th F Sa
1 2 3 4
5 6 7 8 9 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30 31
Forum Stats
12065 Members
14 Forums
16973 Topics
75151 Posts

Max Online: 303 @ 01/28/20 11:58 PM
Top Posters (30 Days)