If the design is to be made in accordance with Part 4 only, may nozzle be placed in knuckle reigeon? does part 4 refers to part 5 in this case?
I see no restriction for the nozzle in knuckle reigeon in VIII-1 and Section I.

_________________
Thanks & Regards,
Nasir
Welding Engineer
DESCON Engineering Limited.
Lahore, Pakistan.
Mobile # 0092-336-4145402

Sec VIII Div 1 - (UG-37) talks about location of nozzles in shells & heads . The formula covers nozzle location in " spherical portion of the dish end " . See definition of tr in the clause.

For locating nozzle in the knuckle U 2(g) applies.

As a result , I avoid the knuckle.

With regards
Rathnam

Rathnam,

I do not agree with you at all.
U-2(g) needs not to comply with if you place nozzle in KR. The definition of tr only gives you credit when you place the nozzle in spherical portion, it does not stop you placing the nozzle in KR.
KR is the highest stressed area of the head, it is true. Better it is to avoid of placing nozzle in KR, it is a good engineering practice.

_________________
Thanks & Regards,
Nasir
Welding Engineer
DESCON Engineering Limited.
Lahore, Pakistan.
Mobile # 0092-336-4145402

Dear Sir

I had written about this earlier also . I am placing it below .

UG 37 talks about reinforcement area required for openings in shell / head sections. This is an old formula based on Hetenyi's Analysis . This formula is applicable in "spherical portion of the formed head' .

So what about Knuckle portion ? What is clear is that this formula can not be used as it does not apply to knuckle. So you get three options as below -

a Stick to the code & don't mess with that knuckle .

b. Use Design by Analysis i.e. use FEM or similar method. This of course has to be reviewed by AI. U 2(g)

c. Use another formula acceptable for this purpose. I am told East German code (yes , there was such an animal) used to give such a formula. Since I have not used this code I can not vouch.

ASME Sec VIII does not prohibit nozzles in Knuckle portion. It is merely silent . Some codes are not silent .For instance, Indian code IS 2825-1969 is very specific and does not permit nozzles in knuckle portion.

Can some one confirm what is correct ?

With regards
Rathnam

Rathnam,

UG-37 intends to say that nozzle in KR is not prohibited, code is not silent on it, you may place in KR.
Now look at the definition of Tr, consider an ellip head and following two cases.

1- When you place the nozzle in specified spherical portion, Tr shall be calculated by considering the head as a seamless sphere and equation 3 of UG-32 shall be used instead of equation 1. The spherical radius L shall be taken equal to K1D, take K1 from Table UG-37 and D is the inside diameter. This formula shall calculate almost half thickness as comapred to ellipsoidal head formula, so UG-37 gives you a credit if you place opening in KR, that is logically true.

2- When you place nozzle in KR, you will calculate Tr by using equation 1 of UG-32, by taking E=1 even if no RT of welded head is performed.

The summary is, code does not stop you placing the nozzle in KR, it contains the rules for the nozzles even in KR then why you go to U-2(g).
Going to U-2(g) is voilation of the code in this case, I do not remember the interpretation that clears that if rules are given in the code, you cannot go to U-2(g).

_________________
Thanks & Regards,
Nasir
Welding Engineer
DESCON Engineering Limited.
Lahore, Pakistan.
Mobile # 0092-336-4145402

Dear fiends, this is a Div.2 Forum and the question is related to Div.2.
Please stay to the issue. In Div.1 this issue has been discussed already.
Mauro