Image Credit: Asahi/America, Inc.  | BI-Torq® Valve Automation | Hamilton     Valve positioners compare a control signal to a valve actuator’s position and move the actuator accordingly. They are used with both linear valves and rotary valves. Valve positioners are used when the 0.2 to 1 bar pressure in the diaphragm chamber is not able to cope with friction and high differential pressures.   Image Credit: Spirax Sarco   The positioner is...
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Q & A on Valve Positioners

We asked our users for their input on Valve Positioners. Here are the results of 136 users familiar with Valve Positioners.

Who Took Our Poll? | Design Trends | Applications and Use | Features | Buying Advice |

Who Took Our Poll?Top

Design TrendsTop

Q:
What new technologies are influencing valve positioner design?
22 answers
Answers:
Smart positioner with automatic calibration; it can also provide the position data to the DCS.
~Albert J, Engineer, Heng-chun, TAIWAN
Foundation fieldbus, increased spool capacity to increase speed diagnostics.
~Len Briddon, Technical Support, Kuala Lumpur, Malaysia
The latest communication technologies have influence in positioner design.
~Mahesh Dungrani, Engineer, Mumbai, India
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Q:
From your perspective, which companies are creating the most innovative valve positioners?
25 answers
Answers:
Fisher ( Emerson), Dresser Masoneilan, Metso etc.
~Bilash M, Marketing/Sales, Kolkata, India
Foxboro, Flowserve and Masoneilan
~Thuan Nguyen minh, Instrumentation & Automation, Vung tau, Vietnam
Masoneilan and Emerson Fisher
~Marketing/Sales, Sant Boi, Spain
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Applications and UseTop

Q:
What are some of the applications you have used valve positioners for?
34 answers
Answers:
Applications that incorporate a combination of either Level, Flow, Pressure, pH, Orp, Conductivity, Oxygen or Temperature Control. In control of water treatment, chemical reaction in a furnace.
~Technical Support/Services, Altona, Australia
Steam pressure reduction, level control, flow control. All of this in linear, rotary and piston valve actuator with low quality air supply.
~Antonio C, Engineer, Ver/Cardel, Mexico
I am still confused when it should be used. In some plants I have seen use of it while for same services in other plant it hasn't been used.
~Ajay TIWARI, Design Engineer, BARODA, INDIA
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Q:
Please share with us any “non-standard” applications that valve positioners have been used for.
9 answers
Answers:
Load the two-stage centrifugal compressor with a double acting cylinder and double acting Siemens positioner. (the two-stage air compressor with 136,000 m3 / h and 11.5 MW steam turbine).
~Bosko Belancic, Leading maintenace engineer, Kikinda, Serbia , Europe
Antisurge recycle/vent with quick dump for fast opening with control for recycle/vent to keep compressor out of surge.
~John E, Control Systems Engineer, Houston, TX
I have used the positioner in split range mode to control the valve.
~Mahesh Dungrani, Engineer, Mumbai, India
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Q:
Do you know of any disastrous mistakes that occurred due to the incorrect usage of valve positioners?
7 answers
Answers:
Electropneumatic positioners have errors especially in hi-vibration pipeline. And they have significant errors. Use digital contactless valve positioners.
~Sansin D, Engineer, Cebu City, Philippines
Misapplication of new positioner in antisurge service with a quick exhaust device to open the valve for recycle/vent on compressor surge protection.
~John E, Control Systems Engineer, Houston, TX
Compressor damage due to heavy back pressure resulting from high pressure loss across the valve.
~Fayez A, Process Engineer, Belfort, France
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FeaturesTop

Q:
What would your design or feature "wish list" be for this product?
18 answers
Answers:
I would like to add the harsh environment qualification in which the smart positioner should work satisfactorily. Like, High Temperature and Pressure environment, Radiation environment etc.
~Mahesh Dungrani, Engineer, Mumbai, India
Valve position sensor must be very reliable, it can not be RVDT which may experience wear out. Positioner must be easy to use, simple to do auto calibration.
~Albert J, Engineer, Heng-chun, TAIWAN
1. Small Air Consumption, Faster Response, Zero Hysterisis, Proper Positioning of Stem & Final Valve Health assessment.
~Bilash M, Marketing/Sales, Kolkata, India
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Buying AdviceTop

Q:
Do you have any advice for people relative to buying or using valve positioners?
12 answers
Answers:
1- Don´t forget to purchase diagnostics software. 2- Don´t forget to train maintenance crew on valves diagnostics 3- Try to find out how much supplier will charge you for software upgrade. 4- Don´t ever biuy a positionr diagnostics that cannot analyse 0% and 100% travel.
~David Rodrigues, Technical Support, Salvador - Bahia, Brazil
Use clean well filtered and dry instrument air > problems with relay shuttle valve causes problems due to contamination causing sticking and erratic action in overshoot
~John E, Control Systems Engineer, Houston, TX
Purchase valve positioners that are digital (smart ) and can have modular communication card in case the plant will upgrade from HART to FIELDBUS OR MODBUS
~Sansin D, Engineer, Cebu City, Philippines
The valve should be chosen in accordance with the type of fluid (density, viscosity etc)
~Fayez A, Process Engineer, Belfort, France
Choose a big brand product, ask for demonstration of easy operation and maintenance.
~Albert J, Engineer, Heng-chun, TAIWAN
Material, temp. range, pressure rating should be correct to application
~Hien Dang, Engineer, HCM, Vietnam
Many companies have some old valves . Mounting kit is very important.
~Bosko Belancic, Leading maintenace engineer, Kikinda, Serbia , Europe
The i/p conversion must be robust this is the hart of the positioner.
~Antonio C, Engineer, Ver/Cardel, Mexico
Use pneumatic positioners for applications need stable and accuracy.
~Thuan Nguyen minh, Instrumentation & Automation, Vung tau, Vietnam
Recommend abb fisher siemens
~Hou Ben, Project Manager, Shanghai, Cn
BE SURE OF YOUR APPLICATION
~ED STEUTERMANN, Manufacturer, LOUISVILLE, KY
Research and compare
~Randy G, Facilities Manager, Northbrook, IL

Q:
Is there any advice you want to share with users to help them avoid common errors in selection or usage of valve positioners?
9 answers
Answers:
Deal with companies that can evaluate and fix their own problems in a timely and efficient manner >> failures at plant cause job insecurities for engineers.
~John E, Control Systems Engineer, Houston, TX
While selecting or designing, special attention should be paid to flow characteristics and effective area (particularly for compressible fluid flow).
~Fayez A, Process Engineer, Belfort, France
1. Always use positioner, actuator and body in the same manufacture. 2. Read manual carefully before using.
~Thuan Nguyen minh, Instrumentation & Automation, Vung tau, Vietnam
If you have valves older than 5 years use positioners with continuous output (Metso, Samson) and not with blocked output (Siemens).
~Bosko Belancic, Leading maintenace engineer, Kikinda, Serbia , Europe
Ask vendor to inform diagnostics capabilities. Don´t buy digital positioners if you are not going to use diagnostics capabilities.
~David Rodrigues, Technical Support, Salvador - Bahia, Brazil
Rapid change is vital; slow change product of low flow in outputs of positioner causes low performance of control loops.
~Antonio C, Engineer, Ver/Cardel, Mexico
Use correct spool valve in the positioner for corresponding size of the control valve.
~Sansin D, Engineer, Cebu City, Philippines
If valve position information is very important, don't use RVDT.
~Albert J, Engineer, Heng-chun, TAIWAN
Active preventive maintenance program should be developed.
~Hien Dang, Engineer, HCM, Vietnam

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