SA-105 or SA-266 for Integrally Reinforced Nozzles 2

[lilili]

It is clear that SA-105 does not include tubesheet and cylindrical shell. I think SA-105 should not be used for integrally reinforced nozzle too, and SA-266 is the right one. Anybody has experience?

Thanks.

 

[chaulklate]

SA-105 does not include tubesheet or cylindrical shell simply because it is not sheet or plate product. SA-105 is commonly used for integral nozzles as manufactured by companies such as Forged Vessel Connections Inc., Forged Components Inc., and Trovay & Cauvin to name a few that I am familiar with.

 

[doct9960]

lilili,

Integrally reinforced nozzle can be of SA-105 material as long as the weight does not exceed 10,000 lbs. See paragraph 1.1 of ASME spec. for SA-105.

 

[jehan17718]

lilili,

Regarding self reinforced nozzles, the hub will be made from SA-266 (Grade 2 typicaly). However, the connecting flange (welded to the hub) if produced to ASME B16.5/B16.47 is used, the same may be of SA-105 provided it is leess than 10k lb.

Please note that though doct9960 has correctly specified that the 10000 lb limitation on the use of SA-105 forgings, one must keep in mind that SA-105 is by definition "Carbon Steel Forgings for Piping Applications". The hub portion consequently cannot be produced from SA-105 specifiction.

Below is the extract from "Scope" section of SA-105 which will be helpful in understanding the SA-105 spec. It is clear from this that hub portion cannot be SA-105.

................"This specification covers forged carbon steel
piping components for ambient- and higher-temperature
service in pressure systems. Included are flanges, fittings, valves, and similar parts ordered either to dimensions specified by the purchaser or to dimensional standards such as the ANSI and API specifications referenced in Section 2. Forgings made to this specification are limited to a maximum weight of 10 000 lb [4540 kg]. Larger forgings may be ordered to Specification A 266. Tubesheets and hollow cylindrical forgings for pressure vessel shells are not included within the scope of this specification. Although this specification covers some piping components machined from rolled bar and seamless tubular products, (see 4.4) it does not cover raw material produced in these product forms."..............

Hope this helps.

-Jehan

 

[doct9960]

jehan,

So for a SA-105 long weld neck flange, do you intend to use a SA-266 hub???

SA-105 may be used in pressure vessel construction. Refer to ASME VIII-1 UG-6, UCS-7, UG-11(a)(1), UG-44(i).

Also refer to this ASME Interpretation...

Interpretation: VIII-1-89-244
Subject: Section VIII, Division 1 (1989 Edition, 1989 Addenda), Use of SA-105 Material
Date Issued: October 22, 1990
File: BC90-656

Question: May the body flanges and hubs of carbon steel pressure vessels that will be built in accordance with Section VIII, Division 1, with inside shell diameters larger than 24 in., be made from SA-105 forgings?

Reply: Yes.

 

[vesselfab]

for long weld necks, A-105 is used for the standard carbon steel. That's what the common material is for our thousands per year in standard lwns, HBs, V1 V2 V3 & full bodied integrally reinforced nozzles.

Normally for hollow tube forgings that a flange, pipe or fitting will be welded to, we also spec out A-105 for carbon steel

For body flanges we also spec out A-105 for carbon steel

The only thing we would not spec out A-105 for standard carbon steel is for heavy forgings over 10,000 lbs or a forging that would be used for a head or shell. Havent used a forged shell or head for years but that's what we would use for standard carbon steel.

 

[jehan17718]

doct9960,

You are perfectly correct to add that a long weld neck nozzle (LWN) can be fabricated out of SA-105. The confusion is in part because I did NOT address in my earlier post LWN nozzles; which are self reinforcing too . Let me be more explicit.

My initial remark ...

"Regarding self reinforced nozzles, the hub will be made from SA-266 (Grade 2 typicaly). However, the connecting flange (welded to the hub) if produced to ASME B16.5/B16.47 is used, the same may be of SA-105 provided it is leess than 10k lb."

....... was strictly oriented towards self reinforcing nozzles having a hub similar to the one shown in fig UW 16.1 (e); which is then welded to a standard B16.5/16.47 flange. In such cases, we typically use SA-266 for the hub and SA-105 for the flange. This is the practice we follow over here. The allowable stress values for both SA-105 and SA-266 (if I recollect correctly) are identical.

You will encounter a very similar "quandary" when it comes to SS flanges and forgings. Standard flanges will be produced to SA-182 while non standard forgings for nozzles will be produced to SA-336.

Regards,

Jehan

 

[lilili]

Except standard B16.5/B16.47 WN and LWN flanges, self reinforced nozzles shall be SA-266.

Reading SA-105 closely, one will note that, except for flanges, materail supplied to this specification does not even have to be forged, it can be machined from hot rolled bars. Also, it is not clear what heat treatment would be applied. If you want a well forged material, SA-266 should be used for non-impact tested forging and SA-765 for impact tested forging. Both require to follow forging requirements per SA-788.

 

[vesselfab]

Someone better tell the manufactures

FVC is one of the largest self reinforced nozzle manufacturers and the use a-105 all day, every day