Rtj flanges 1

[vessexst]

Hi all,

Can anyone tell the standard for a lwn rtj nozzle flange??
I checked out in asme b16.5 but I only found WN Rtj type flanges.

Are there no standard lwn rtj type flanges available?? Are they custom made??
I am working on a vessel having a pressure of 210 bar and 2500 ID. The client wants a lwnrtj 30" nozzle. At such a high pressure, lwn nozzle requires a reinforcing pad with it. I found no rtj type nozzle in pv elite also. It only gives a wnrtj type.
Any suggestions?? Asme B 16.5 does cover lwn nozzles by the name of straight hub flanges but I did not find rtj type for a lwn nozzle.

 

[r6155]

See

https://www.texasflange.com/images/Catalog/catalog-c-v5.pdf

Regards

 

[vessexst]

@r6155: Thanks for sharing. However, my question remains the same. Are rtj type flange facings available for lwn nozzles?? If yes, then where to find standard for lwnrtj flanges

 

[LittleInch]

The flange sealing type can simply be used for any applicable flange.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[r6155]

See ASME B16.20 and B16.47, not B16.5

Regards

 

[vessexst]

@littleinch: I am asking because lwn nozzles are forgings so flange and pipe are an integral forged part unlike Wn flanges. The purpose of asking was that if a lwnrtj nozzle is a standard nozzle and if yes, then which standard??
Or, should these nozzles be custom made

 

[Geoff13]

I believe what you are looking for is the straight hub welding flange in B16.5 clause 2.8. No idea why they don't call it a long weld neck like everyone else. The RTJ facing dimensions are in Table 5.

 

[vessexst]

@geoff13: Yes I know about the dimensions of rtj in asme b16.5. However,my question is of the lwn flanges are also rtj type?? The rtj, flanges, as per my understanding are WN only. However, in case of lwn, flanges is an integral forged part with the nozzle.
I did not find lwnrtj in asme b16.5

 

[r6155]

ASME B16.5 covers the dimensions of the long weld neck flanges.

ASME B16.5 2.8.2 Length Through Hub. The length through hub
shall be 229 mm (9 in.) for NPS 4 and smaller and 305
mm (12 in.) for larger than NPS 4. Other lengths may
be furnished by agreement between the end user and
manufacturer

Regards

 

[vessexst]

@r6155: Ok I think maybe I had poorly put forward my question. What I meant to ask was that "do lwn nozzles have a rtj type flange or not??"
And the reason why i am asking is because lwn nozzles are forgings, so have a standard flange according to dimensions given in asme b16.5 (that I knew of)
However, do these flanges (of lwn nozzles) have a "RTJ" type flange face or not??

RTJ flange dimensions are given separately (I know this)
But, what I understand, is that these are stand alone rtj type flanges that are welded with nozzlw necks (making a WN type nozzle)

I did not find, in the standard, lwn type flanges having a rtj flange facing.
Are they avaialable?? If yes, then are they custom made or avaialable easily?

I hope i have clearly put forward my question again

 

[Geoff13]

Perhaps the best source for an answer would be to phone one or two manufacturer's. Only they will be able say what's off-the-shelf for them vs. what's a custom item, and the answer will be diferent for each company

 

[r6155]

vessexst: why you cannot find figure 4 in B16.5?
Try to do a minimum effort to understand.
See B16.20.

Regards

 

[LittleInch]

vexxesxt

Your questions above

1) "do lwn nozzles have a rtj type flange or not??"

In ASME B16.5 LWN flanges are called "Straight hub welding flanges". What type of flange facing you ask for is up to you and, like every other flange type, if you want to use RTJ, then you use the dimension provided in table 5. It is no different to any other type of flange so YES LWN flanges can be supplied in RTJ type.

2) "And the reason why i am asking is because lwn nozzles are forgings, so have a standard flange according to dimensions given in asme b16.5 (that I knew of)
However, do these flanges (of lwn nozzles) have a "RTJ" type flange face or not?? "

WN flanges are also forgings. See above, If you ask the manufacturer for RTJ, you'll get RTJ.
Many flanges AFAIK, are forged suitable for any flange face. If you want RF, they just machine off the excess metal. If you want RTJ, they machine in a groove.


3) RTJ flange dimensions are given separately (I know this)
But, what I understand, is that these are stand alone rtj type flanges that are welded with nozzle necks (making a WN type nozzle)

your understanding is not correct. Table 5 (RTJ flange faces) are applicable for ANY type of flange. including "straight hub welding flanges" aka LWN

4)"I did not find, in the standard, lwn type flanges having a rtj flange facing.
Are they avaialable?? If yes, then are they custom made or avaialable easily?"

Your issue though is at 30" and 210 bar, so class 1500, you are beyond any current standard size and rating for ASME B16.5 or 16.47 or MSS SP-44 type flanges, so you're into a "special" design already. What is specified on the drawing / design? Or are you doing it?

A flange this size and this pressure rating requires a bespoke design, probably to ASME VIII. I don't know of any standard that goes that big at that pressure.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[vessexst]

@littleinch: Great reply!!!!
Got my answers

 

[LittleInch]

Great. However we haven't got your answers, I.e, what design are you going to use for such a large high pressure flange?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[r6155]

vessexst. Is this nozzle 30" for manhole?

Regards

 

[vessexst]

@littleinch: Well, the shell thickness was coming out to be 106 mm. My lwn nozzle of 30" was not passing without a pad. Then I put a reinforcing pad with a thickness of 110 mm with a 200 mm width.
But i am thinking of going to a full body FVC type or an insert plate option may serve the purpose.
What do u suggest??

@r6155: No, it is for inlet gas
(And my initial had an error. The pressure is 110 bar)

 

[LittleInch]

I know about flanges, not pressure vessels....

Well 110 bar is in the realms of B16.47 class 900 so rather better than 210 bar...

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[r6155]

@vessexst
Ummm!. Now is 110 bar instead of 210 bar?. I wasted my time!
You should contact an pressure vessel engineer.
good luck.

r6155