Actuators, Regulators & Other Final Control - Recent Threads

RE: FIELDVUE DVC6200 to FEEDBACK HART Conversion

Pop Alexandra — Thu, 11 Jun 2026 07:57:27 GMT

A HART-based solution sounds like a very sensible approach in this situation. Since the DVC6200 positioners already support HART communication, you can potentially retrieve valve position feedback, diagnostics, travel, alerts, and other status information digitally without adding 92 dedicated analog input channels. This would significantly reduce I/O requirements while also providing much richer information than a simple 4–20 mA feedback signal.

_______________________

Alexandra from RDC Control

FIELDVUE DVC6200 to FEEDBACK HART Conversion

Victor Blanco — Wed, 07 May 2025 16:12:44 GMT

We have ninety-two (92) FISHER control valves with FIELDVUE DVC6200 positioners in stock for a project that will be reactivated soon. Due to modifications to the control strategy, it is now necessary to obtain the feedback signal from each positioner, but due to control system limitations, it is not possible to add the hardware for 92 AIs. The option we are exploring is to add the necessary hardware to each positioner and implement a HART serial system that collects all the status information and delivers it to the control system. If necessary and advisable, the control signals (AOs) could be included in this HART serial system, but for now, we are only interested in the AI feedback signals. We formally request EMERSON's support and guidance to obtain the best solution for this requirement!

RE: FIELDVUE DVC6200 to FEEDBACK HART Conversion

Victor Blanco — Thu, 08 May 2025 16:42:05 GMT

Yes sir!

www.plant-process.com
Phone: (281) 333-7762
Email: victor.blanco@plant-process.com

RE: FIELDVUE DVC6200 to FEEDBACK HART Conversion

Riyaz Ali — Thu, 08 May 2025 16:04:14 GMT

You are welcome Victor. Could you please advise your phone number, email details so that our impact partner FIELDVUE Champ can contact you.

RE: FIELDVUE DVC6200 to FEEDBACK HART Conversion

Victor Blanco — Wed, 07 May 2025 22:05:42 GMT

Hi Riyaz,

Thank you very much for your prompt assistance. We are located at 18333 Egret Bay Blvd, Suite 320, Houston, TX 77058.

We look forward to welcoming you.

RE: FIELDVUE DVC6200 to FEEDBACK HART Conversion

Riyaz Ali — Wed, 07 May 2025 20:28:51 GMT

Hi Victor, If AO (4-20mA) to DVC6200 from control system has HART Pass then you should be able to map valve travel (using HART Command 3) into control HOST system. if you can advise your exact geographical location, may be Emerson local sales office or local impact partner can support your technical needs.

RE: DCMLink and TEC2

Hussein Abdulwahid — Wed, 22 Jan 2025 17:35:28 GMT

Hello Anthony

Thanks for you kind reply

I’ll be in field within a week and I’ll try that.
Yes the Bluetooth is enabled, so it could be that why it’s not connecting.

Kind regards

DCMLink and TEC2

Hussein Abdulwahid — Tue, 21 Jan 2025 12:47:09 GMT

Hello

We have upgrade Tec2000 actuators to Tec2 , as in the upgrade manual its written to use DCMlink to access Tec2 setting, back and change them.

However, when we tried to connect to Tec2 with RS485 and DCMlink via pin 36 and 38 , there is no response from the Tec2 CCM card ( I assume it's the one responsible regarding the modbus communication ).

It is fully functional when it comes to open and close the valve and can chang the setting from the LDM, but I could find the TEC2 with the DCMLink (always nothing found)

So, I would be very grateful if one of you can guide me to make it work and establish a connection between TEC2 and DCMLink

Kind Regards

RE: DCMLink and TEC2

Anthony Kmitta — Wed, 22 Jan 2025 14:09:29 GMT

Thanks for reaching out.

You are correct that the TEC2 has a dedicated DCMlink Modbus connection on Pin 36 (-) and Pin 38 (+).

Settings for the Modbus connection in DCMlink should be:
Mode: Modbus Master
COM Port: The port of the adapter
Baud Rate: 115200
Parity: None
Stop Bits: 1
Timeout Delay: 1000
If Bluetooth is enabled, you will need to check the ‘Encryption’ box. If Bluetooth is not enabled you can leave encryption unchecked.

If you need further assistance, please reach out to our Life Cycle Services group at Actuationsupport@emerson.com

RE: Control valve discharge flow exceeds requirements which makes the valve to oscillate often.

JMoscovic — Thu, 09 Jan 2025 23:08:46 GMT

A valve should control between 20 and 80 %. This is the wrong CV, most likely the wrong valve size. Controlling between 20 and 80 % reduces many valve and control problems like stiction and reset windup.

Control valve discharge flow exceeds requirements which makes the valve to oscillate often.

E15 — Fri, 20 Dec 2024 14:31:42 GMT

Hello experts and [mention:cfe879b68fab4703b2dd4ea56b5f6cff:e9ed411860ed4f2ba0265705b8793d05]

We have a Fisher control valve calibrated for a 0-100% span corresponding to 4-20mA. However, with less than 2% valve opening, the discharge flow exceeds the downstream requirements, causing the valve to repeatedly open and close, resulting in oscillations.

The valve is a 2-inch model, recently calibrated, and the operating range of the process line should be 0-8%. I dont have much information at this time?

To address this, would adjusting the valve span to map 0-8% to 4-20mA help stabilize the system? Alternatively, should we consider replacing the valve with a 1-inch valve or installing a back-pressure regulating valve helps?

Expert in the house, which option would be most effective and reasons?

RE: Control valve discharge flow exceeds requirements which makes the valve to oscillate often.

Jeffrey Mach — Thu, 09 Jan 2025 22:43:54 GMT

I am going to concur with the others that say, if your control valve will only open 2% for the operating range of your process, it is not correctly sized.

Re-ranging the entire command span to represent the 0-8% opening is unlikely to help, as the problem likely is the valve is having difficulty modulating only a small amount, as opposed to signal issues (unless you knew of an obvious source of noise or other signal error). Also note that you initially said that you are exceeding the desired output at 2% open, so even 8% valve opening at 100% command means that the valve would be being given a maximum 25% command, if linear, under normal operation.

If you can reduce the input pressure to the valve (and that does not negatively impact the process), then you should be able to achieve a smaller change in flow relative to a larger change in valve position, which should give the valve much better control authority, and you should be able to tune the input pressure to optimize your control. Is it even practical to knock the pressure down to the point that your valve would be open at 50% under normal operation, which would give it the maximum control authority?

Replacing the control valve would be optimal (don't need an additional / altered pressure control), but would likely be a more expensive solution. You mention a 1" valve. Is that mentioned because it is readily available? If your 2" valve is already over-flowing your target rate at 2% open, I'm not sure a 1" valve is nearly small enough to help. There are many additional factors, but ballparking a 1/4 reduction in the cross-sectional area is not a lot relative to the need to increase your control authority more than an order of magnitude.

If there is ever a thought that you might need to increase the flow rate in the process at a later date, reducing the control valve size permanently reduces the maximum available flow (relative to the maximum available line pressure upstream of the valve).

RE: Control valve discharge flow exceeds requirements which makes the valve to oscillate often.

Jawad Waheed — Mon, 23 Dec 2024 07:47:45 GMT

I see no need for that here.

RE: Control valve discharge flow exceeds requirements which makes the valve to oscillate often.

E15 — Mon, 23 Dec 2024 02:58:41 GMT

Thanks Eapen Mathew and Jawad Waheed. How about replacing with back-pressure regulating valve will that help also?

RE: Control valve discharge flow exceeds requirements which makes the valve to oscillate often.

Jawad Waheed — Sun, 22 Dec 2024 06:01:24 GMT

Yes this seems to be the problem, that you have oversized the valve, because only at 0 to 8% you get the flow you need. If you want to save yourself from the cost of the new valve, then I suggest you should try to calibrating the range 0-8% as 4-20mA. This might help also.

RE: Control valve discharge flow exceeds requirements which makes the valve to oscillate often.

Eapen Mathew — Sat, 21 Dec 2024 07:03:12 GMT

It appears the 2"-inch valve is oversized for your current process condition.
You should consider changing to 1" valve after reconfirming the process condition.

Steam flow control valve

john — Thu, 06 Oct 2022 14:44:15 GMT

I have a flow control valve for steam, where the trend across 4 months period shows that the valve opening is different, for the same PV. Meaning the valve opening is going from 64% up to 90 something % for a steam flow of almost constant around 70t/hrs. Any reason why such variation in the control valve ? If there is a problem , any way to troubleshoot this and what parameters to look at ?

Thank you

Your thoughts please

Thank you

SIS Requirements for valve assemblies

Jake Parsons — Fri, 19 Aug 2022 19:48:21 GMT

How does emerson define SIS requirements for valves? From what I have seen the general consensus is that the "final element" is rated to IEC 61508 standard. Where the "final element" notation stops is where I am having the issue. We have pneumatic shut off valves going back to the SIS system. The solenoid valve that controls air to the actuator has an IEC 61508 certification but I cannot find the same certification on any valve or actuator. Is there a comparable ISO standard that the mechanical elements follow or am I not looking hard enough for IEC 61508 valves and actuators?

RE: SIS Requirements for valve assemblies

Jake Parsons — Mon, 22 Aug 2022 12:30:18 GMT

Thank you Riyaz. I just looked at our SIL certs on our instruments and they do include that line on being IEC61508 rated. I should have everything I need.

RE: SIS Requirements for valve assemblies

Riyaz Ali — Fri, 19 Aug 2022 20:55:20 GMT

Emerson have Valves & Actuators, which meets SIL suitability requirements in line with IEC61508. If you can send me your email, will guide within Emerson team to furnish copy of certs.
Unlike electrical / electronics components, Mechanical items have more deterministic failure rate, depending upon applications, process fluid, fluid physical properties, operational history, maintenance records, environmental conditions, test philosophy, etc. Though mechanical items, on its own do not have self diagnostics, like Microprocessor based Digital Valve Controller, Final Element may be dominate SIL budget during PFDavg calculation. Certainly, diagnostics coverage can be improved (to provide better PFDavg) by utilizing Smart Microprocessor based intelligent device, which can replace existing SOV or can be added pneumatically in series with existing SOV. There are microprocess based devices, which also have the capabilities to diagnose accessories like SOV etc., mounted between smart device and actuator.

RE: Valvelink Database Export/Import

Amr Temraz — Wed, 20 Apr 2022 09:41:57 GMT

Hi Shaiq,

Yes, a multi-tag export file from ValveLink Solo to AMS ValveLink SNAP-ON and same for ValveLink SNAP-ON to another ValveLink SNAP-ON.

Please note that when working with ValveLink Solo to ValveLink SNAP-ON imports in a new devices are going to show up as spares in the AMS database.

Hope this helps.

Best regards,
Amr

Valvelink Database Export/Import

Shaiq Bashir — Mon, 18 Apr 2022 19:42:32 GMT

I would like to know the following:

1) Is it possible to export the database from Valvelink SOLO version and import it in AMS Device Manager with Valvelink SNAP ON (with different system ID)?

2) Is it possible to export the database from AMS Device Manager with Valvelink SNAPON and import it on the system with different system ID?

Regards

RE: Valvelink Database Export/Import

Lorraine Driscoll — Tue, 19 Apr 2022 11:50:01 GMT

Q1) yes. Use the Export tag Data... function in ValveLink SOLO under the Tag tab. To import into AMS DM use the import ValveLink Data. Right Click on AMS Device Manager at the top of the tree in explorer view
Q2) Yes. Use the same method as question one except for use valvelink snap-on for both import and export.

RE: Control valve flashing

Greg Dawes — Thu, 07 Apr 2022 19:35:55 GMT

Hi John, This response is from Hank Penner, one of our Senior Instructors in Educational Services:

The minimum capacity specified for a valve and trim set are based on several considerations. First each trim set has a clearance flow that is a result of the trim design. Globe valves , for example, exhibit a clearance flow based on the clearance between the cage and the plug. When the controlling flow area is reduced to the point at which the clearance area becomes more significant, the flow across the valve becomes less and less a function of valve position. Valve gain is reduced to the point where it no longer controls and instability may result.

Secondly, control valves operating very low in travel experience accelerated trim wear. You mentioned cavitation. Trims designed to eliminate or minimize cavitation damage often use a staged or divided pressure drop in their design. If the throttling point becomes more restrictive than the staging, higher pressure drops across the plug and seat will concentrate the cavitation across the seating surfaces, leading to an increased damage potential.

Having said all that, control valve wear and damage mechanisms are all time-based. Problem is the definition of “short time”. All control valves have to be able to transition from fully closed to a position it is design to control. Lengthening that transition to include a plant startup may result in finding that point at which the accelerated wear and damage may become noticeable. Adding cavitation can significantly accelerate the damage. This point is highly process dependent.

I know of no field on the ISA standard control valve data sheet that is specific to flashing. The valve sizing report does indicate flashing. If the valve outlet pressure (P2) is less than the thermodynamic vapor pressure (Pv), the process is flashing. If you are dealing with a mixture, if P2 is below any constituent vapor pressure, it is flashing.

Thanks again Hank!

Greg Dawes | Director, Educational Services |
Greg.Dawes@Emerson.com

Control valve flashing

john — Tue, 05 Apr 2022 21:11:28 GMT

Hello

Question please,

Can I operate a control valve at low flow rate/valve opening for a short time (during startup for example ) even if I know at this point, flashing or cavitation may occur? I will be operating the valve at a value less than the minimum flow rate the valve is sized based on.

Also, does the valve datasheet show when flashing occurs or I have to do calculation again for that purpose ..

Your inputs please from experience

Thank you..