Allowable Stress for 32760 heat Exchanger material 1

[bmoorthy]

1) Noting that ASME Sec II D does not provide Allowable stress for Super Duplex grage 32760 (A 182 F55 Equivalent) for all product form, is ok to have a heat exchangers made from 3270 Plates, 32760 forgings etc since TEMA addresses these material.

2) Can 32750 allowable stress be used for 32760 alloys.

3) Is there a code case, i understand there was a code case 1853 for super duplex, does this address 32760?

4) One of the supplier broucher indicates 190 N/Sq MM as the allowale stress at room temperature, can value be used as allowable stress for 32760 tubes?

 

[metengr]

bmoorthy

1) Noting that ASME Sec II D does not provide Allowable stress for Super Duplex grage 32760 (A 182 F55 Equivalent) for all product form, is ok to have a heat exchangers made from 3270 Plates, 32760 forgings etc since TEMA addresses these material.

Reply; No, if the heat exchanger is built to ASME Section VIII, Div 1, and requires a U stamp. Otherwise, you can fabricate to TEMA and other standards.

2) Can 32750 allowable stress be used for 32760 alloys.

Reply; No, allowable stresses should be determined for each grade of material, regardless.

3) Is there a code case, i understand there was a code case 1853 for super duplex, does this address 32760?

Reply; Can you provide a date of this code case? I did a quick search and could not find it as active.

4) One of the supplier broucher indicates 190 N/Sq MM as the allowale stress at room temperature, can value be used as allowable stress for 32760 tubes?

Reply; Unless you know how the allowable stress was determined, I would not use it.

 

[bmoorthy]

A) The exchanger is not U stamp

B) If i have to design to TEMA and generall in accordance with ASME and use ASME values, then how to get the allowable stress for material like 32760, especially for Flanges and for tubes

C) I came across Code Case 1883 (Sorry not 1853) in Ferralium's Broaucher where code case 1883 is refered against 32750/32760. In the same broacher, isee they declare the alowable stress is 190 N/Sq MM

http://www.nationalmetaldistributors.com/download/Ferralium Leaflet.pdf

 

[metengr]

I did not see a code case active for 1883. This means that it either did not get ratified or there is a typo somewhere. I checked on my C&S connect for ASME B&PV code committee members and I saw nothing for 1883.


Also, I checked the same brochure and if you read the fine print, this code case was not ratified at the time the brochure was printed.

So, you are at your OWN risk if you decide to use the allowable stress values stated in the brochure.