Steel Grade A-70 Clarification? 3

[NickelMet]

We have a tank that the documentation (dating back to the early 1940's) states there is some part of it made with "A-70 FBX" steel. I understand FBX means FIREBOX. However, none of my resources go back far enough to capture what the A-70 spec entails. I'm assuming a carbon steel.

Does anyone know about this material or can point me in the right direction to find out information?

Thanks
~NiM

 

[metengr]

NickelMet;
Assuming the A 70 is an ASTM A70 Specification for Low and Intermediate Tensile Strength Carbon steel plate, this specification was withdrawn in 1947 and was replaced with ASTM A285. The ASTM A285 specification contains three grades of carbon steel plates A thru C.

 

[metengr]

NickelMet;
I might be able to track down a copy of this particular ASTM standard. One of my former mentors, who is now in the big met lab in the sky, used to keep old ASTM Standards, which I now have inherited for my own library. When I get back to the office on Thursday, I will check the archives.

 

[NickelMet]

Thanks Metengr. That would be really helpful. I have code books back to 1949, so the tidbit on being withdrawn in 1947 helps.

What I'm really looking for are the allowed stress values. The steel was used to construct propane bullets back about 1942-43. We're looking to set minimum temperatures on these, taking into account brittle fracturing as a possibility.

Any help you can provide will be greatly appreciated.

Thanks again!
~NiM

 

[unclesyd]

Adding to metengr's post one has to assume that there was no NDT performed unless there is a specific reference to same on the vessel or documentation. Being built during the war is doubtful that it was tested under the A300 standard. We had several butane/propane bullets that were built in the late forties that originally had no NDT nor impact testing. I don't recall the MOC.
I've seen a lot of this material on fireboxes and ovens.

You can get copy of the ASTM A70 Standard from:

Global Engineering documents globalcustomerservice@ihs.com Phone: 800-854-7179 or 303-397-7956

Or

http://www.lindahall.org/

They may also be able to supply you the ASME Code UCS tables for this material.

 

[NickelMet]

Thanks Unclesyd. I have a Global account, but I couldn't find the document there. (I'll try again.) And I have used the Linda Hall organization before.

~NiM

 

[metengr]

NickelMet;
It is your lucky day. I contacted one of my fellow main committee members at the NB, and they sent me a copy of the allowable stress values for ASTM A-70 S1 carbon steel plate material from the 1945 Edition of the ASME B&PV code;

A-70 S1

allowable stress temp
11 Ksi ambient to 700 deg F
10 Ksi 750 deg F
8 Ksi 800 deg F
6.750 Ksi 850 deg F
5.5 Ksi 900 deg F
4 Ksi 950 deg F

 

[NickelMet]

WooHoo!! We're in business!!! Thanks a lot Metengr!!

~NiM

 

[InspEngr]

I'm looking at the 1943 API-ASME code and get different values than metengr reported. I believe the reason would be that API & ASME used to work together for the pressure vessel code (we also have a 1934, First Edition, API-ASME code). At some point they split. I had heard that the API-ASME used a 4:1 safety factor and that the ASME (back then) used 5:1. This would jive with metengr's data as A-70 is listed as a 55,000psi tensile strength material. Here's what's listed:

13750 -20 to 650
13050 up to 700
11550 750
9900 800
8250 850
6600 900
4950 950
3400 1000

-InspEngr

 

[NickelMet]

InspEngr:

That information will work too. We'll run the figures from both sets just for comparison.

thanks
~NiM

 

[JoeTank]

InspEngr,

You are correct in those years ASME VIII used a 5.0 factor of safety. API-ASME used 4.0.

Historically, ASME and API-ASME were never same Code. They were always separate Codes intended for different industry segments. API-ASME was withdrawn in early or mid-1950's after ASME was reduced to a 4.0 factor of safety. No reason to have two Codes with same F of S. The intro to API-510 gives additional info.

Steve Braune
Tank Industry Consultants

http://www.tankindustry.com

 

[NickelMet]

THANKS to everyone on the information that was provided. We were able to use the information to run the calcs as we needed to AND update our equipment information books appropriately.

~NiM