Why SA-240-TP 316Ti not listed in ASME sec II D, table 2A

[jtseng123]

Dear all,

We have a slender C.S. equipment that is designed per Div 2, Class 1 to meet design pressure and specific metal thickness for heat transfer purpose. If using Div. 1, it will be too thick and not fit the purpose.

On the vessel body there is an expansion joint the material is SA-240-TP 316Ti, but it is not listed for Div 2 use. (It is allowed in Div 1).
Why can it not be used for Div 2 ? and is there any suggestion to solve this problem ? The design temperature is only 300F. Thanks.

 

[TGS4]

It's not there because no one has asked for it. As a short term measure, you could get a Code Case.

Do you have anyone in your company that participates in the BPVC? You should attend the next meetings in Atlanta in November.

 

[EdStainless]

Why on earth would you need to use a stabilized alloy for 300F service?
The other solution is to use 316L.

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P.E. Metallurgy, Plymouth Tube

 

[MJCronin]

I am guessing here that the SA-240-TP 316Ti,was selected to be used on the HX due to availability ???

I know that this material is in widespread usage internationally, but not so much in the USA.

Can you tell us where the expansion joint came from ?

MJCronin
Sr. Process Engineer

 

[XL83NL]

Wouldnt a TP grade be (expected to be) found in SA312 (pipe) rather SA240 (plate)?

 

[jtseng123]

This is similar to double pipe heat exchanger with outer CS pipe having an expansion joint to absorb different movement. 316Ti is selected due to water with salt, as advised by client.
Can fabricator use Div 1 allowable stress for 316Ti but use Div 2 Part 4.20 to design the expansion joint and still be code stamped to Div 2, Class 1 ?

 

[TGS4]

To answer your second question: no.

 

[EdStainless]

I hope that this water has very little salt (maybe 10ppm) and a high pH (8 would be nice).
Otherwise 316 stands no chance at 300F.
It will be a race to see if pitting or SCC catches you first.

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P.E. Metallurgy, Plymouth Tube

 

[MJCronin]

...."316Ti is selected due to water with salt, as advised by client".....

Anyone ????/ Ed Stainless ???????????

https://www.eng-tips.com/viewthread.cfm?qid=87879

MJCronin
Sr. Process Engineer

 

[weldstan]

Poor advice from client. You will need a superior alloy.

 

[jtseng123]

Our alternative is SA 240-TP 321 such that Div 2 can be used.

 

[weldstan]

Another poor choice in chloride environment at 300F. Think about a nickel chrome moly alloy.