High Temp Pressure Vessel Question - Incoloy 800HT 1

[belfour30]

Hello,

My customer is looking for a pressure vessel that can handle 950C and 50psi in a 50% 02 environment. I've spec'd Incoloy 800HT but I can't find any S values at these conditions. I am awaiting my BPVC-VIII code book in the mail, hopefully that will have it. But in the meantime I just want to do a sanity check.

In addition, I will need threaded rod that can withstand these same conditions....I'm hoping to find someone that can make 10-32 rod out of 800HT but I'm not sure.

Any information is appreciated - thank you!

Matt

 

[metengr]

The ASME SB 407 Incoloy 800H is permitted for use at 950 deg C (1742 deg F), the maximum permitted use is 1800 deg F . Alloy 800HT is limited to 1650 deg F.

 

[TVP]

1650 F is the maximum temperature limit shown in Section II, Part D, Table 3 for the following bolting alloys:

* UNS N06002 (Hastelloy X®, Nickelvac® HX, Nicrofer® 4722, Altemp® HX, Inconel® HX)

* UNS N08810 (Incoloy® Alloy 800H)

* UNS R30556 (HAYNES® 556® Alloy

 

[belfour30]

Thank you metengr and TVP - as you can see I'm right on the edge and I'm getting conflicting reports.

If I specify the UNS N08811 alloy for Incoloy I can get to a higher temperature, right?

Thanks again.

Matt

 

[TVP]

No. Until you get the ASME BPVC, take a look at this document, specifically pages 6-7:

http://www.specialmetals.com/documents/Incoloy alloys 800H 800HT.pdf

 

[metengr]

Just to be sure with no confusion, as mentioned by TVP, Alloy 800HT is not permitted for use above 1650 deg F as bolting material or as pipe or tube product forms. As I mentioned above, Alloy 800H supplied under ASME SB 407 seamless pipe and tube is permitted for use at a maximum service temperature of 1800 deg F. There was a Code Case for seamless pipe and tube product forms which finally became endorsed by ASME Section II, Part D, Table I for allowable stress values (2007 Edition, 2009 Addendum).

By the way, the stress values for Alloy 800H at 1700 deg F, the allowable stress is 0.71 Ksi, for 1750 deg F, 0.56 and for 1800 deg F , 0.44 Ksi.

Bolting as supplied under ASME SB 408 for Alloy 800H is still limited to 1650 deg F as mentioned above.

 

[belfour30]

OK - thanks again for all of your responses. I rec'd my BPVC but I only ordered Section VIII/Division 1 - I don't see any stress values in it. Do I really need to order Section II part D???? What a scam!!

 

[metengr]

Do I really need to order Section II part D???? What a scam!!

Yes. Actually, Section II contains various parts in addition to stress tables (Part D) - Parts A (ferrous material specifications), B (nonferrous material specifications), C (Specifications for Welding Rods, Electrodes and Filler Metals), and D.

 

[belfour30]

Ok, thanks. I just found the table of contents for the entire B&PVC code book - I had no idea it was so inclusive. In that case, would it be possible to get the range of allowable stress values according to Section II Part D starting at 1000F and going up in 100 degree increments? Any help is appreciated.

 

[metengr]

belfour30;

By the way, the stress values for Alloy 800H at 1700 deg F, the allowable stress is 0.71 Ksi, for 1750 deg F, 0.56 and for 1800 deg F , 0.44 Ksi.

.

14 Ksi @ 1000 deg F, 11.6 Ksi @ 1100, 7.4 Ksi @1200, 4.7 Ksi @1300, 1.1 Ksi @1600

Interpolate between values.

 

[belfour30]

All,

I finally rec'd Section II Part D and I have an issue. P. 246 lists the Incoloy Alloys N08811 and N08810 and MAXIMUM service temp is 1650 - metengr where are you getting the values up to 1800F?? I don't see anything in either of the addenda's.

Any help is greatly appreciated, thanks!

 

[metengr]

belfour30;
2009 addendum of Section II, Part D, Table 1B

look at page 243, line 39, for UNS N08810, maximum permitted temperature is 1800 deg F. Keep in mind this is for seamless pipe and tube.

On page 246 you are looking at forgings and welded pipe/tube, bar and plate. These products are limited to 1650 deg F.

You will have to decide if your vessel can be built out of pipe versus forgings, welded pipe or plate to take advantage of the higher permitted service temperature.

Otherwise, a Code Case could be one option for your application.