B898 is it OK in ASME Exchanger

[bmoorthy]

The ASME 2004 Section 2B does not list (s) B898.

Where as B 898-05 (For Cladded Titanium) ASTM standard declares that the cladded material is good for pressure vessels. In fact it gives reference of ASME.

B 898 further delves on Welding repairs and even permits overlay.

Where as UNF of ASME Sec VIII Div 1 2004(Including 2006 addenda) clearly prohibits welding of titanium with any other material.

Is this an aberation or am i missing some thing??

 

[eliebl]

If the material is not listed in Table UNF-23 of ASME then it cannot be used for that code of construction.

As a side note I did see a stainless tubesheet with and explosively bond layer of Zirconium which required an interlayer of Titanium for compatibility. I wouldn't want to make an error on that design.

EJL

 

[MJCronin]

I am curious about clad titanium...

What is the purpose of each layer ?

Does the titanium provide an explosive bond to the base metal wheras the Zirconium would not ?

What kind of fluids require such exotic metalurgy ?

Where, on the internet, can I find out more about the bonding process ?

thank you and best regards......


-MJC

 

[eliebl]

I believe the interlayer was so that the zirconium would properly bond to the tubesheet. The tubes were then Zirconium and welded with a helium leak test.

I do not know off hand the application but I believe it was pretty nasty.

EJL

 

[deanc]

MJCronin

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