Material Selection for Long Weld Neck Flanges

[msii]

Hi,

I have a question regarding selecting proper material for LWN flanges for class 1500# in pipeline (B31.8 or AS2885) with material of API5L X70 and X65.
Design pressure: 20 Mpa
Design Temp.: 0-60 C
Is ASTM A105 non normalized accepted for this temperature?
How about A694 F65? which one is prefered in pipelines?

Thanks

 

[LittleInch]

The 105 material is ok, but it's lower strength means that it has a large change in wall thickness at the end of the weld neck which is difficult to bridge by use of weld metal.

A694 F65 is a better material, but you need to use MSS-SP-44 spec and not ASME B 16.5

I would use A694 F65

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

 

[msii]

Thanks LittleInch
Do they need be normalized for 2NB and 6NB?

 

[msii]

Any thought on normalizing?

 

[BJI]

Yes, they should be normalized.

 

[msii]

What is the reference?

 

[BJI]

MSS-SP-44, 4.1. Normalize or Q&T.

 

[DGrayPPD]

From the 2010 edition of MSS SP-44:

4. HEAT TREATMENT

4.1 The F42 and higher grades of flanges of
all pressure classes and the class 400 and higher
classes of Grade F36 flanges shall be
normalized or quenched and tempered.

 

[msii]

thank so much guys