What is CV in Control Valve | MOST Simple Explanation

Flow coefficient (Cv) is defined as the number of gallons per minute (gpm) at 60°F that will pass through a full open valve with a pressure drop of 1 psi.
Valve Flow Coefficient (Cv) is a valve’s capacity for a liquid or gas to flow through it. It is technically defined as “the volume of water at 60°F (in US gallons) that will flow through a valve per minute with a pressure drop of 1 psi across the valve.”
When selecting valves, choose the closest to the calculated Cv, typically rounding down unless a specified maximum ΔP of a project is exceeded. An oversized valve may cause control issues such as hunting or poor heat transfer (delta T) across a coil due to overflow. Conversely, an undersized valve may not provide enough flow and exceed available ΔP.
The relationship between pressure drop and flow rate through a valve is conveniently expressed by a flow coefficient (Cv)
Cavitation in control valve : In a control valve, if the liquid's pressure falls below its fluid vapor pressure, vapor bubbles will form and these bubbles burst after the pressure is increased beyond the vapor pressure curve is called cavitation in control valve
Flashing and cavitation in control valves : In a control valve, if the liquid's pressure falls below its fluid vapor pressure, and if the downstream pressure remains below the vapor pressure of the fluid, the process condition is called flashing.
Choked flow control valve : Choked flow is the point at which decreasing downstream pressure will not increase the flow through a valve. At this point the velocities are the highest and cavitation at this stage is very severe.
#cavitationindexincontrolvalve #sigmacalculationincontrolvalve #controlvalvecavitationindexcalculation #Control Valves #Controlvalves #cavitation #flashing #chockedflow #cavitationincontrolvalve #flashingandcavitationincontrolvalve #chockedflowcontrolvalve #realpars #instrumentation #valves #instrumentationinterviewquestionandanswers
🔴FREE E-Book on Engineering PIP Standards 🔴
www.asad-shaik...
( 🔴 ) Link to FREE Udemy Course for I&C Professionals
1500+ Engineers have taken the Course
(Engineers have said it is even BETTER than the PAID Courses available)
Give it a Try 😊
asad-shaikh-in...

[@AsadPassionateEngineer]

🔴Link to Instrumentation Crash Course for Professionals (FREE course) 1500+ Students have already taken this course. 👉asad-shaikh-instrumentation.ck.page/06e66ac455 Students have said to make the course course PAID (Because of the value they received from the course) Let me know your feedback

[@purnakiran580]

How to covert Cg to Cv.. can someone please give the e formula

[@naileshmaheta8622]

Please make video on Compressor instrumentation like Seal gas system/Trip logics/different types of probes used in it along with principals

[@craighudy4196]

The honey vs water comparison notes the cause as honey being very dense when the issue is actually honey have very high viscosity. Unfollow this channel unless you want to make stupid mistakes like this guy.

[@vijaysisodiya-tc8yl]

Dear sir How to calculate max flow through a control valve when we have a CV/kV value of a valve .

[@ankurbhatnagar3241]

Well explained Asad. In control valve series, Could you please explain how to select right CV for any process.

[@AsadPassionateEngineer]

Sure Brother !! This video was especially made after your request !! 😊

[@balajiarni]

Very well explained. Excellent material & lecture than college professors. Best wishes Bro!!

[@AsadPassionateEngineer]

Thank you so much, I really appreciate your comments and motivation a lot !! 😊👌

[@saquibkhan1230]

Please make a video control valve seat leakage calculation.

[@AsadPassionateEngineer]

Sure. I am working on it ........ Should be ready in couple of weeks. I.A

[@MyShaikali]

Nice

[@sasikumarragupathi]

Can you please explain stem buckling calculations of Control valve

[@munjulavishwanth2640]

Would you make a video which gives a detailed explanation about selecting a right valve size with correct Cv. With an example of vendor sizing calculation sheet . Also explain about velocity acceptable range in sizing calculation

[@nivethanive821]

Knowledgeable video🙌..,please share how to choose a valve type and its application. And also share about the flow characteristics of control valve

[@AsadPassionateEngineer]

Sure Nivetha, yes these are amazing topics will make a video on these topics in the very near future !! Inshallah 😊

[@dharmendradp602]

Very useful video, I request you to make a video and notes on selection criteria.

[@AsadPassionateEngineer]

Noted Dharmendra 😊. thanks for your comment !!!

[@anirudhaghadel3688]

Please make a video on how to calculate leakage rate of butterfly and throttle damper

[@sanaurrasheed]

Plz make videos in hindi urdu also..

[@AsadPassionateEngineer]

Sure dear 😊 inshallah in the near future !!

[@prashantdhokiya3767]

Very nicely explain, Clear all doubt of cv

[@ercankr75]

Good tahank you teycher

[@AsadPassionateEngineer]

most welcome 😊

[@cck1496]

Good video. What about flow in cubic metres/hour? Does CV mean that it the highest flow the valve can accommodate? Thanks.

[@AsadPassionateEngineer]

Rated CV if valve means the highest flow the valve can accommodate. CV can be at Normal, Min or Max operating conditions as well. hope I was able to answer your query

[@vsaktharhussain]

Very much informative❤❤informative article

[@grandhivenkatachalapathira1588]

Nice video, Can you please discuss in detail? Whatever Cv that is mentioned for any valve, is it at complete open condition of the valve?? Is it the philosophy?

[@AsadPassionateEngineer]

Yes, The valve manufacturer's publish rated CV of the valve which is the CV at maximum capacity of the valve.

[@mohammednizamuddin5613]

Hats off for your videos Special thanks for descriptions & request you to make video or add in description regarding solutions for flashing & cavitation and its bad effects on valves

[@AsadPassionateEngineer]

Happy to know, it was helpful! 😊 based on your comment, i am making a video on solutions to cavitation and flashing it will be out very soon Inshallah !!

[@tariqueanwer9329]

Sir, Really I appreciate your work & what a simple way of explanation of each topic. Your all videos are very unique and informative. Thanks for your efforts.

[@AsadPassionateEngineer]

So nice of you for this Kind feedback. Glad you found the efforts useful. 😊

[@divyangpatluwala7425]

knowledgeable video...please share How to calculate CV for various fluids. please 🙏

[@AsadPassionateEngineer]

Sure !! I would love to make a video on this topic. Thanks for your comment. And glad you like the video 😊

[@nikilmahi6834]

Thank you for the informations❤

[@SyedHamedinstrumentation]

Very well explained asad bhai please I want to learn more about control valves

[@AsadPassionateEngineer]

Sure Brother, Will make more videos on Control Valves, Please let me know if there are any specific topic that would be useful to you !!

[@anjujoy3976]

Very informative video🙂 can you please tell why cv is more popularly used compared to kv value in a control valve?

[@AsadPassionateEngineer]

The flow factor (Kv - in Metric unit) - the amount of water that will flow in m3/hr. with a temperature range 5 to 30 °C and pressure drop of 1 bar. While The Valve Coefficient (Cv - in Imperial unit) - the number of US GALLON PER MINUTE of water at 60 °F that will flow through a valve at specific opening with a pressure drop of 1 psi across the valve. Overall the vendors have adopted the Imperial units around the world hence in order to keep uniformity for comparing various valves CV is preferred as compared to KV. Hope i have been able to explain your query 😊 And this is a good question thanks for asking 👌

[@mohsenk5985]

Merci à vous, c'est super.

[@tariqueanwer9329]

Very nice explanation

[@harshilshah4641]

Today finally understand this topic !! 👍👏

[@AsadPassionateEngineer]

Thanks for your comment, it made my day!!!

[@Arizona807]

It's nice video and informative

[@AsadPassionateEngineer]

Thank you so much !!! so glad to know that it was helpful !!

[@anirudhaghadel3688]

Lots of information as usual ❤️👍

[@AsadPassionateEngineer]

Most welcome !! and thank you to you for your constant support. 😊

[@sanjaybagul7314]

Very well explained

[@AsadPassionateEngineer]

Thank you Sanjay 😊

[@wsiddig1]

Thanks Asad.

[@AsadPassionateEngineer]

most welcome 😊