π " Three Times Better (Engineer) "
The 3 Things You will learn today are as follows.
β’ One Engineering Learning :Sizing a Control Valve is not easy.But if you check these 26 Points you are SAFE.
β’ One Engineering Standard : Control Valve Sizing Standards
β’ One Career Tip from Top Professionals : How Elon Musk Learns so much more than others (How I learnt Analyzer Systems)
Before we start.
Quick Announcement.
I just published something,
That might change how you think about "Control Valve Sizing"
Called Engineer's Guide to Control Valve Sizing- Version 1.0β
This is a No-Nonsense guide. [With No Theory]
It has
- Algorithms
- Mind-Maps
- And Practical stuff (No Theory).
That will instantly make you 10x better in control valve sizing.
βHere is Google Drive Link to Download it [For Free]β
Enjoy upgrading your engineering skill-set.
PS: Please note this is the Version 1.0
β
And I will be proof reading this in parallel and would like your suggestions as well
β
On how can this guide be made the best resource on the planet for sizing valves. (Each reply is appreciated).
#1 -Engineering Learning
How did the below (26 Point) checklist checklist come into existance.
- I have sized 1000's of valves as part of my job.
- Then I spend 2000+ Hours learning valves.
- And then sharing my knowledge on youtube.
- And then sharing via 50+ hours of that in Zoom Calls.
- In the ACV (Advanced Control Valve Cohort).
So below is a summary of all the points that should be checked in control valve sizing as a minimum by any engineer.
A systematic Approach to Control Valve Sizing via Checklists
1. Process Data & Fluid Properties
Garbage input yields dangerous garbage outputs.
Verify the following.
- Min, normal and max flows
- The Shut-off DP must be provided.
- Specific Gravity and Viscosity.
- Vapor Pressure and Critical Pressure.
- Verify your software measurement units twice.
Summary: Accurate process data drives accurate sizing.
β Action Example
Never mix up kg/hr and lb/hr. (A common mistake)
2. Piping Geometry Factors
Fluid hitting a reducer loses pressure.
Think of it like electrical voltage drop.
Valves are often smaller than pipes.
This sudden area change restricts flow.
Include the Piping Geometry Factor (Fp).
Summary: Account for pressure loss from reducers.
β Action Example
Add reducer dimensions into sizing calculations.
3. Valve Travel & Controllability
An engine runs best at mid-RPM.
A control valve acts the exact same.
Avoid operating near the extreme edges.
Keep normal travel between 20% and 80%.
Ensure minimum flow stays easily controllable.
Keep it above the minimum stable clearance.
Summary: Give the valve room to modulate.
β Action Example
Select a Rated Cv comfortably above 20% of Max Calculated Cv.
4. Cavitation, Flashing & Choked Flow
Water hammer shatters solid steel pipes.
- Cavitation destroys valve trims the same way.
- Flashing also causes erosion.
- Choked Flow limits the valve output
If pressure drops too fast, mitigate it.
There is an entire algorithm to mitigate it.
You will find it in the Engineers Guide to Control Valve Sizing E-book.β
Summary: Ensure the valve can handle such harsh conditions.
β Action Example
Using anti-cavitation trim for minor incipient cavitation is a waste.
5. The Aerodynamic Noise Limits
Can you stand near a Jet ?
A jet engine creates deafening, destructive vibrations.
Gas at high velocities does too.
Check if aerodynamic noise exceeds 85 dBA.
Evaluate the most cost-effective solution first.
- If noise is massive, use Source Treatment.
- If noise is borderline, use Path Treatment.
Summary: Protect human hearing and pipe integrity.
β Action Example
Use a Whisper Trim for massive noise reduction.
β Action Example
Wrap pipes in acoustic insulation for minor excess.
6. Dirty Service Constraints
Complex valve trims get stuck with solid particulates.
Avoid Balanced Trims in dirty fluid service.
Particles jam inside the small balancing holes.
- Avoid Multi-stage Trims for large debris.
- This is critical if particles are > 19 mm.
Summary: Keep trim design simple for slurries.
β Action Example:
Select a robust, unbalanced trim for dirty fluids.
7. Material Compatibility
Using carbon steel in sulfuric acid is an engineering sucide.
Select materials matching the exact fluid.
Check the body and trim metallurgy carefully.
- Ensure it handles extreme process temperatures.
- Ensure it withstands highly corrosive environments.
Summary: Chemical compatibility dictates the valve lifespan.
β Action Example:
Specify NACE compliant materials for sour gas.
8. Actuator Selection & Muscle
Take care of the below points for Actuator Selection
- Size it for Maximum Shut-off DP.
- Choose Diaphragm or Piston type correctly.
- Calculate torque using Minimum Air Supply.
- Verify casing survives Maximum Air Supply. (If it cannot, install a pressure relief valve.)
Summary: Ensure the actuator physically moves the valve.
β Action Example:
Calculate thrust against worst-case differential pressure.
9. Failure Modes & Accessories
Define the fail-safe action very clearly.
- Fail Open
- Fail Close
- Fail Last.
Verify your spring rates or air reservoirs.
Check the positioner and external accessories.
Ensure they match Hazardous Area Classifications.
Summary: Design the entire valve (Actuator, Plug Type, Electricity failure etc) to assist the fail action.
β Action Example:
Specify an explosion-proof positioner for Zone 1.
It is difficult to cover all the points in this email,
But if you want the 26 Point Excel on Control Valve Sizing
Read Below to get the Excel Checklist for future use.
Want 26 Point Excel on Control Valve Sizing
Reply "Control Valve Sizing Excel Checklist"
And I will share it with you immediately. (Since it is ready)
#2- Engineering Standard
π Let us Geek Out.
Can you tell me which IEC or ISA standard is used
for 2 phase control valve sizing ?
The Right answer to this will get a special mention
In the next newsletter with his linkedin profile displayed in this newsletter.
That is sent to 10,000+ of the world top I&C engineer so you can build more meaningful and thoughful network.
Want to be a Control Valve Subject Matter Expert in your company.
Hop on the Waitlist of ACV 2026 here.β
#3 -Career Tip
Elon Musk Learning Method.
Elon Musk knows
- Finance
- Software Engineering
- Rocket Engineering
- Electrical Engineering
So hate him or like him.
He knows something about learning that we can learn.
The Tree and Leaves Method.
What I learnt when I studied about him was.
He does not randomly learn.
- He will first look to only get an overview.
- (Which he calls trunk of the Tree).
- Then sub-break it down to branches.
- Then sub-break it down to leaves.
Let me share an example
How I learnt about Process Analyzers
Don't start learning with which carrier gas to be used in the GC Analyser.
Rather first break the System into Sub-Systems.
A typical system will include the following units or components:
- Sample handling system
- Analyser (the sensing unit)
- Calibration system
- Environmental shelter
- Utilities
Now Sub-divide the sub-system into further sub-system.
Example : Of the above-mentioned components the sample handling system is the crucial & most often the weakest link in the system.
Basically the sample handling system consists of 4 elements:
- Sample take-off point.
- Sample transport system to the analyser.
- Sample conditioning system.
- Sample return and/or disposal system.
So if you do a focused learning session like this.
You can master any field.
This is what I learnt spending 100+ Hours learning about him.
Hope this helps in your learning journey as well.
How was today's learning
Highly Valuable : Reply 1
Somewhat Valuable : Reply 2
Needs Improvement : Reply 3
I see each feedback reply as a gift.
Until next week,
Happy Learning & Keep Smiling.
Asad Shaikh
Your Instrumentation Friend!! π
See you next week!
β