ASME VIII CODE

[ratutxa]

Hi everyone,
Our company need to manufacture water filters under requirements of ASME VIII and IX. The designing is given to us by our customer that is who shell the equipment to the final customer. The filters are composed basically by a shell of thickness 20 mm and flanges acc. to AWWA standard class E of ND120", internally the filter has some parts of duplex stainless steel material (UNS32205) welded to filter.
I was wondering if is it mandatory by the code to make a post weld heat treatment to the equipment?.
Thanks for your answers.

 

[SnTMan]

Which Division?

 

[ratutxa]

Division I

 

[weldtek]

If you're fabricating and stamping these to ASME Sec VIII Div 1 you must have a copy of that Code. It doesn't sound like these are going to fall under 'lethal service', if they're carbon steel refer to UCS 56 for the requirements regarding PWHT.

 

[ratutxa]

weldtek, we are fabricating but not stamping, the fluid is water and they are carbon steel with an austeno-ferritic stainless steel. We are in course of getting the U stamp but we aren't who design the equipment and our customer hasn't request the U stamp, I don't know if this one is correct. I have checked the UCS56 but it is quite confusing, I can't fix which are the requirements to have a post weld treatment.

 

[metengr]

ratutxa;
It appears you are a subcontractor to the company that designed the vessel. You would not be in a position to stamp if you are fabricating a component for the vessel. However, the requirements for fabrication should be supplied by the company that is taking responsibility for the design.

 

[weldtek]

Just to be clear, other than the few exceptions for parts allowed in UG 11, if you're fabricating and welding a part for a stamped pressure vessel, you as the fabricator must stamp and supply a signed data report ( U2A ). It sounds like in this case the vessel or part isn't stamped, but designed and built per the ASME Code. As Metengr says the best thing to do is ask your customer for direction regarding PWHT.

 

[jwhit]

I can visualize a major problem with PWHT of this material combination. If you heat treat to stress relieve the carbon steel you risk creating inter-metallics and sigma in the duplex portion of the filter. If you heat treat to dissolve inter-metallics you will ruin the carbon steel's mechanical properties. I know this doesn't totally follow the discussion but may be worth thinking about.

 

[ratutxa]

Thanks a lot, I'll request our customer to clarify regarding PWHT.