V-Port/V-Notch Ball Valve Design

[prasadr]

Hi All,

I am new in the valve industry. I am trying to understand ball valves and their application fields. From the study I have done so far, I came to know that for flow regulation applications, v-port/v-notch ball valve is used. I tried searching online about the design procedure of v-port ball valve but I did not find anything.
So, my question is how to design a v-port or v-notch ball valve? What are the geometrical parameters which affect the design of the v-port ball? What international standards documents are followed for the designing process? Can you please tell me the name of those documents?

Thanks

 

[LittleInch]

Design procedure?? You would need to work for a valve manufacturerer to know that

Have you tried searching "V notch ball valve design" ?? plenty things out there

Geometrical parameters - have a look here

https://resources.bray.com/en/sales...s/f-2600-v-control-ball-valves-sales-brochure

International standards - none I'm aware of

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[prasadr]

Thank you LittleInch. I just read your reply. I sincerely apologize for the delay in response. Yes, I have searched for "V notch ball valve design" and I found various brochures. I know there are v-notch ball valves with different v-angle like 15,30,60,90 degrees. What I don't understand is what changes in the design of v-notch ball valve results in different flow amount and flow characteristics. So that's why I asked about geometrical parameters which affect the design in terms of flow performance. Also, I have read that there are various standards like API, ASME for valve design. But I don't know which documents industry people follow for designing the v-notch ball valve.

Thanks

 

[LittleInch]

Well that's the skill of the valve designer. essentially you have a variable sized orifice, but as it's not a circular one but a strange shape that keeps changing you probably need to build one and test it to get the CV vs opening. Clearly a smaller hole equals lower flow for the same percent open.

The shape of the opening will vary the CV to percent open characteristic. I think that's proprietary valve company design stuff.

In terms of the main valve code, all is concerned the thing is a ball valve. The fact that the ball has a hole in it is irrelevant.

So ASME B 16.34, API 6D, ISo xxxx etc will all still apply.

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

 

[gerhardl]

Hello prasadr,

To find aabetter approach to answer your question I suggest you study the different applications and use for v-notch ball valves. What is the demands and sought solutions for the market/users you are designing for?

As all regulating valves a correct design is depending of fluid type and flow parameters (variations in pressure, temperature, amount, viscosity, etc.) for each application.

The flow is roughly proportional to the exposed opening if laminar flow. A long, small slit will regulate better for smaller amounts compared to the max flow for the diameter.

The rest is adaption to the general average use for a market segment or to the exact adaption for a single case, plus knowledge, tests and patience...

 

[prasadr]

Okay. Thank you LittleInch and gerhardl for your responses.

I will try to reach manufacturers to get the design concept of v-port as well as will try to understand market demand.

When one knows about they should use a v-port ball valve rather than other types of control valves?

Are there any particular benefits of v-port ball valves?

 

[LittleInch]

I've always thought of V port valves, rightly or wrongly, as being relatively low differential pressure and where you need to have tight shut off when closed.

They ar euseful when you only need control on certain occasions and then want as low a pressure drop as you can when fully open. Or a controlled start over a period of time and then full flow.

They are also limited in fluids to avoid cavitation.

You'll probably find some who really like them and use them and others who hate them. I can't say how many get used, but I would guess no more than 10-15% of the control valve market.

http://www.dwyer-inst.com/Articles/?Action=View&ArticleID=67

http://www.valve-world-americas.com...vs-globe-valves-for-control-applications.html

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

 

[prasadr]

Today, in another thread, I read about the segmented ball valve.

According to my knowledge, the segmented ball valve has no full-bodied ball. It has a half ball and it is used for ON/OFF applications.

But in the thread which I read, people were talking about the half-ball in the valve having v-notch/v-triangular slot on its convex side and preferred flow direction is from inside the body (against the concave inner side of shell/ball).

I never saw in any image that segmented ball valve is having v-notch on its convex side.
So, does this kind of valve design actually exists?

And if it does exist, are industries using it for flow regulation?

Thanks

 

[LittleInch]

Indeed. Never seen one of these before now, but you learn something every day.

https://0c074d522cc96a09f3a6-cd6844...f7.ssl.cf2.rackcdn.com/F-2306_S19_2015-09.pdf

clearly some industries do - this one quotes pulp and I suppose it is a little like a knife valve in its closure action.

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