Ball size confusion 1

[NDS_21]

Hey
Greetings!
I got a 1" reduced bore and 1" full bore 3-piece ball valve. Now if I just concentrate on middle main body piece of both the valves the difference I observed was due the size of the ball (obviously due to difference in bore).
Now my question is if the ball outer diameter is kept same and only the inner bore is made as per reduced bore or full bore size then apart making different seats for both, what would be the disadvantages of doing it?
One thing I can think of is the torque requirement for reduced bore will increase because now the ball size will be bigger.
Anything else am I missing here?
THANKS IN ADVANCE
(P.S. I am trying to learn something new everyday)

 

[Danlap]

Hi,

Refer to answer from bcd in below thread will answer your question

http://www.eng-tips.com/viewthread.cfm?qid=20283

Not to be generalized, ball valves are usually preferred for quick opening/closing (whether hand operated or actuated), therefore typically used for drain line and relatively medium sized lines or smaller for battery limit application e.g. between vessel and filling boat/truck, oxygen/nitrogen supplier to gassifier, etc.
Some special application might requires bigger (more than 6" ball valve) as ESDV, BDV, dumping valve and pipeline application. But this is usually custom made and full bore is quite common to be specified due to PIG-able requirement

End user POV:
Refer to Cv value, some Process engineer find it less significance the difference for ball valves FB and RB with sizes less than 4", so they can bare accepting cheaper reduce bore ball valve (operation would love this part also). As for bigger sizes, since ball valve will be bulkier, heavier and more expensive. Plus not preferred for non-clean/abrasive/erosive application, so the demand for bigger size ball valves is limited

manufacturer POV:
Its a competitive world, procurement/planner from end user side will not consider FB or RB valve since they do not deal directly with Process, they will only summarize whether manufacturer A vs B is expensive or cheaper for same size/class/material Ball valve. Plus imagine if you are a big manufacturer who produce hundreds of small ball valves per day. It would be faster and less step required to produce RB instead of FB. With FB, there are some extra material, machining, and dimension control required. Which means extra cost to be charged to customer whom mostly "don't care" whether it is FB or RB.

Kind regards,
MR

https://nosuchvalve.com

All valves will last for years, except the ones that were poorly manufactured; are still wrongly operated and or were wrongly selected

http://www.eng-tips.com/faqs.cfm?&rat1=2&fid=376

 

[NDS_21]

Okay the response from @bcd is amazing and thanks for providing me the link to that @danlap
Now I guess I'm much more clear with the concept of keeping the same ball.
(P.S. Forum is great to learn new things everyday with this many experts to teach you)