Flange SA-105 Normalized VS Flange SA-105

[hcjulien]

Hi,

Can you please tell me when the B16.5 SA-105 flange manufacturer needs to normalized them versus not do it? I can't find the justification of the ''N'' (SA-105N) for some sizes/class of flanges versus others (SA-105 only). Is it linked with the nominal size of the B16.5 flange? Or the class of the B16.5 flange?

Thank

hcjulien

 

[eliebl]

ASME Section II A contains the material specs for SA-105. This is where it stipulates the mandatory normalizing.

EJL

 

[doct9960]

Paragraph 5.1 of SA-105 does not really stipulate mandatory "normalizing" on certain piping components, but rather mandatory "heat treatment". Heat treatment may be annealing, normalizing, normalizing & tempering, quenching & tempering.

 

[doct9960]

hcjulien,

Flanges that require mandatory heat treatment are the following:
1. Flanges above Class 300
2. Flanges of special design where the design pressure at the design temperature exceeds the pressure temperature ratings of Class 300, Group 1.1
3. Flanges of special design where the design pressure or design temperature are not known

 

[jehan17718]

hcjulien:

From ASME Section II Part A perspective normalising of SA-105 is required as per para 5 as under:-

5.1 Heat treatment is not a mandatory requirement of
this specification except for the following piping components:
5.1.1 Flanges above Class 300,
5.1.2 Flanges of special design where the design
pressure at the design temperature exceeds the pressuretemperature ratings of Class 300, Group 1.1,
5.1.3 Flanges of special design where the design
pressure or design temperature are not known,
5.1.4 Piping components other than flanges which
meet both of the following criteria: (1) over NPS 4 and
(2) above Class 300, and
5.1.5 Piping components of Special Class2 other than
flanges which meet both of the following criteria: (1) over
NPS 4 and (2) when the working pressure at the operating
temperature exceeds the tabulated values for Special Class
300, Group 1.1.
5.2 Heat treatment, when required by 5.1 shall be
annealing, normalizing, or normalizing and tempering or
1 For definition of Class 300, see ASME B16.5.
2 For definition of special class, see ASME B16.34.
200
quenching and tempering in accordance with Specification
A 961.

From ASME Section VIII-1 perspective normalising of SA-105 as per clause UCS-66 will result in the same going from Curve B to Curve C. Also please review UCS-66 c clause which automatically sets -20 deg F as MDMT for ASME B16.5 and 16.47 standard components.

Hope this helps.

-jehan

 

[stanweld]

Normalizing is specified by Purchasers to provide greater uniformity of product. Reforging billets can be "lost" in the furnace with resultant grain growth such that grain sizes of ASTM 1 and greater have been seen. This results in extremely poor impact toughness of the forging. Normalizing provides some grain refinement which provides some additional safety in service.

 

[vesselfab]

we normally see it also in hydrogen & sour services because of the somewhat refined grain structure