"RT" Namplate Stamping

[UKCats]

I have a 1968 "U" stamped pressure vessel not registered with the National Board. I do not have a U1 form.

The vessel's nameplate has the shell and head thickness stamped on it and using these as-fabricated values, it doesn't pass the code using joint eff of 0.85.

The Code Nameplate merely has "RT" stamped on it not RT-1, RT-2, RT-3, RT-4.

I don't know what the practice was back in 1968??? Does a stamping of "RT" on the nameplate mean Full, Spot, or User Specified???

 

[jamesl]

Not sure about 1968 code. According to 1971 code, RT on nameplate means the whole vessel was RTed. If only part of vessel is RTed, use PRT on nameplate.

 

[UKCats]

thanks... It allows the vessel to pass the fitness-for-service evaluation and the nomenclature makes sense... RT and PRT

 

[unclesyd]

Is the material of construction stamped on the vessel?
I don't see how you could do very much without the material of construction.

Is there any thing like a serial number on any name plate. A lot of times there were 2 name plates on vessels. The second plate could have the manufacturers name and serial number on it

In the 1965 code 100% radiography was XR and partial was PXR.

 

[UKCats]

I got my hands on the 1968 Code. RT and PRT was the designation for Full and Partial. Ours is RT (Full). My vessel passes.

The Code nameplate also lists the shell material/thickness (SA-515-70/0.9375, FQ) and head material/thickness (SA-515-70/0.4375, FQ).

I've always wondered what is the difference between Flange Quality steel and Pressure Vessel Quality??? Does anybody know. I don't think it's merely the grain size, that's provided in SA-515 and SA-516. Is it heat treatment??? Normalized vs Not-Normalized, What is it???

 

[metengr]

"Flange quality steel" can be supplied cast or wrought form, so you have various material specifications to choose from in ANS/ASME 16.5

Pressure Vessel plates are only wrought form and may require specific melting practice and heat treatment (depending on thickness) practices.

 

[UKCats]

What is the difference between cast and wrought??? I have this old paradiem that wrought is the old, pour quality wrought iron which had high carbon and slag, which I don't think that's its modern meaning. I've never been able to find a good definition for wrought.

Doesn't cast steel have a little more Si for pourability???

 

[metengr]

Ok, high level explanation. Wrought means that after the steel has been poured (cast), the cast material is shaped into final product form for use. For example; rolling operation to produce plates or forging to produce plates, cylinders or bar, etc. The benefit of working the ingot is to alter the as-cast grain structure, which results in eliminating chemical segregation and establishing more uniform properties in the final product form.

If a material is supplied in a cast form, this implies final shape with no working performed.

Both cast and wrought forms begin with proper melting practices during steel making. Wrought by no means implies an inferior product. Silicon is added to deoxidize the steel, and it does enhance fluidity during pouring.

 

[UKCats]

Great website... thanks

 

[unclesyd]

Here is the wrought iron that you are probably confusing with a wrought (worked) product as described above. The main use of wrought iron is for artistic or restoration work on architectural projects.
I have numerous items made by my grandfather from wrought iron in the twenties and thirties.

http://www.realwroughtiron.com/wiac.asp