14 " Trunion mounted Ball valve

[Rovshan]

I would like to purchase 14" Trunnion mounted Ball Valve, Metal seated, FB. for Low temp service.

Manufacture offered 1 casted piece(body) and 2 forged pieces(ends). Honestly saying this is new to me. As I know body is supposed to be the same material ( I mean Forged or Cast but not combined)
Please share your thoughts....If need additional info let me know

 

[LittleInch]

Is it flanged?

Then a forged end is common surely?

A drawing would help....

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[Rovshan]

RF 600Cl, trunnion-mounted ball valve.
At this stage, there is no drawing. They say: 3 piece valve with Cast body and Forged ends. Is it normal practice?
I have never faced before

 

[LittleInch]

I assume they are using a cast weld end body and just welding on forged class 600 flanges?

Sounds ok to me.

What's your problem with this? Why do you say it has to be one type?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Rovshan]

Honestly saying I have never seen such kind of configuration before. Also taking into consideration that cast and forged material strength are not the same I consider is not practicable.
Could you please advise any reference link to back up such options?

 

[JustABallValve]

I have seen this before in 1500# TMBV, at the end of the day you as a customer will have to accept the BOM or ask for what you want.

I believe its just a cost savings practice by the manufacturer.

 

[Danlap]

All pressure containing parts e.g. valve body, (forged) flanges end, etc. are subject for similar hardness and tensile requirement. if they pass then it is acceptable, at least from strength point of view, regardless where they were originated from.
See A961, one exception is from bar with restriction up to 4". Bigger than that, some companies provide extra supplement such as all three axial, longitudinal and tangential impact test. Why bar is restricted? then is another lengthy discussion of its own.
The general principal of (interpreting) ASTM, ASME, etc. is basically if there is no written restriction then it is allowed.

Another example, different topic, API mandate minimum wall thickness of let say gate valve. But this not necessarily govern what the minimum (bore) internal diameter should be. I've seen some cases where ID of a valve is bigger then ID of its adjacent piping, eventually resulting damage on spiral wound gasket's inner ring.

Kind regards,
D

 

[LittleInch]

A 14" valve is a bit of an "odd" size. Maybe they only have a 14" casting available in WE, not with flanges and can't be bothered to make one just for one valve?

At the end of the day you're buying a valve to a certain spec, material and end to end dimensions. How the vendor makes that is up to them so long as the adhere to the technical requirements of the valve and the material and do all the testing. If the valve body passes the pressure test then it should be good no? Same thing with the materials so long as the meet the minimum requirements for strength and composition.

If you don't like it then don't buy it.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.