Centrifugal casting as per ASTM A451?

[nottoobright]

Hi All
I've recently been asked to quote my product with female threaded fittings (12 3/4") made by centrifugal casting as per ASTM A451. Normally I roll and thread (SS304) in house or buy a seamless tube and thread. What is the advantage to centrifugal casting over seamless tube? Costly? This is a new process to me so any details whatsoever would be appreciated.

 

[arunmrao]

It is not customary to centrifugally cast when a seamless pipe of required wall thickness is available in the market. Centrifugal parts demand a premium price over the sand cast ones.While a few high Ni alloys may not be available in pipe form these are centrifugally cast. Oil and fertilisers industries are major users of spun pipes.

 

[EdStainless]

Cent cast tubes are very common as furnace tubes opperating at high temperatures. It is an efficent way to make tubing when the variations in surface finish and wall thickness are not a problem for you.
How do you plan on putting the threads into the cast tube?

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http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[nottoobright]

Hi EdStainless

Thanks to both you and arunmrao for your replies. In answer to your question, we normally weld a fitting onto the tube. If we did casting of the fitting, we would thread it on a cnc lathe.
The reason for my question in the first place was specifications I saw from a job in Africa that asked for the threaded fittings to be either made from seamless thick walled tubing, centrifugal casting, or forging. I've never used forging or centrifugal casting and don't see any advantage to it unless, as Arunmrao mentioned, there is no seamless pipe of the required thickness.

 

[rconner]

This is a late response to the original inquiry, but I believe some centrifugally cast products, like other castings, have generally less specific grain orientations/distortions than for example those made by other metal forming practices such as rolling or forging etc.; also, while I don't think I have any specific experience with your material nor application, I think some centrifugal products can also result in greater "dimensional stability" in some applications/fabrications than others (see e.g. the research noted at

http://www.acipco.com/centrifugal/casting/heattreating.cfm,and

in other reference).

 

[rconner]

Oops sorry (link somehow got run on) -- please try instead

http://www.acipco.com/centrifugal/casting/heattreating.cfm.