Cast steel weldment

[DavidLX]

Hi,

From foundry respones, they suggested to divide one part into two for casting, then welded together. The material is A217 WC or C. Does anyone has experience to do so for pressure vessel? Any knowledge based on casting weldment or rule (code)?

Thanks!

 

[BlueEngineer]

I have not personally seen this done but it doesn't appear that the code prohibits this type of construction.

If you haven't started looking already, you should pick up a copy of the code and start reading at UG-7.

Per ASME Section VIII Div 1: UG-7 CASTINGS
Cast material may be used in the construction of pressure
vessels and vessel parts. Specifications and maximum
allowable stress values for acceptable casting materials are
given in the tables referenced in UG-23. These allowable
stress values shall be multiplied by the applicable casting
quality factor given in UG-24 for all materials except
cast iron.

As far as that particular material goes, there isn't a A217 WC or C (without a number following the grade) listed in the ASTM A217 standard. The material strength and resistance to certain degradation mechanisms varies greatly depending on the grade.

SA 217
Grade (Generic Name)
WC1 (Carbon 1/2 Moly)
WC4 (1/2 Chrome-1/2 Moly-1 Nickel)
WC5 (3/4 Chrome-1 Moly-3/4 Nickel)
WC6 (1-1/4 Chrome-1/2 Moly)
WC9 (2-1/4 Chrome-1 Moly)
WC11
C5 (5 Chrome-1/2 Moly)
C12 (9 Chrome-1 Moly)
C12A (9 Chrome-1 Moly Vanadium Modified) *Very Particular Material*
CA15 (12 Chrome 1/2 Moly)

All of the materials above are in ASME Section II Part D with allowable stresses provdided.

-Blue
Mechanical Integrity Engineer
5 Years Experience (Refinery)

 

[metengr]

If you go the route of double seam welded manufacture make sure that you require full volumetric examination of the double seam welds.

 

[DavidLX]

tlbdhf,

I do use ASME BPVC for design and analysis for certificate (steel casting valve). But I don't have too much experience on weldment. I can consult ASME and AWS codes about weldment, however, I still want to know some special concern about casting weldment for pressure vessel structure. My bachelor is metallurgy, I know the casting is different from forged plate on microstructure. Do ASME and AWS codes apply on casting weldment flawlessly? Any more concerns about design, heat treatment and inspection?

Thanks!

 

[metengr]

Do ASME and AWS codes apply on casting weldment flawlessly? Any more concerns about design, heat treatment and inspection?

Do they apply? It depends on the design pressure of the casting and use in service. If ASME Code governs for the casting there are requirements for heat treatment, welding, examination and applicable design factors for long seam welds.

 

[vpl]

DavidLX

Is this a pressure vessel or a valve? I'm asking because of your other post in forum 408 (thread408-319428). While the answers might be the same, they also might not.

Patricia Lougheed

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[DavidLX]

vpl and Patricia,

This is valve, but need to conform to ASME BPVC (Valve is knid of pressure vessel too). That's why I questioned it on both sides because I don't know where is better to put it. So far, all replies from this group. Maybe I need to delete the topic in valve group. Let me know how to do it.

Thanks!

 

[stanweld]

The two cast halves may be welded together. If you design and construct to ASME VIII, Div. 1, (U stamp not required because the valve is outside its Scope), the requirements for WPS qualification, preheat, PWHT,NDE, etc. of the weld apply as per metengr.