Valves Forum - Recent Threads

DVC6200 didn't response to DeltaV input

Daniel Lou — Fri, 30 Jan 2026 03:03:36 GMT

DVC6200 is used in DeltaV and AMS environmen. Now in DeltaV control studio shows that AO module out and BKCAL_OUT were in red with cross mark. It stopped to response DCS input. DVC6200 could be open in AMS and ValveLink Snap on. We found there is no any alert and is in "In Service" mode. In DeltaV diagnostic, OInteg is BAD, Status is “Configuration Scale Does Not Match Device”. We checked input range at device is 0%-100% which is same as AO module setting.

After change mode from In service to out of service and back to in service, this issue is resolved.

What is the reason and what should I do to prevent this happen again. Thanks

Daniel

Intrepretation of a brand new butterfly valve signature from Valvelink

Shaiq Bashir — Wed, 04 Sep 2024 16:12:42 GMT

Dear All

We have a brand new butterfly valve with fisher DVC6200 PD positioner. Attached is the signature we have taken from Valvelink for this valve assembly. Can you please help me interpret it as it does not look normal.

Secondly, the blue line represents the signal from close to open or open to close?

Regards

RE: Intrepretation of a brand new butterfly valve signature from Valvelink

Ron Hager — Wed, 11 Sep 2024 14:46:13 GMT

It looks like tuning rather than mechanical. I can’t see much because the graph shown is limited in any detail but look at the increasing stroke (Blue line) and see all the hash from seat to stop. Now look at the return line (red), no hash and looks to be pretty smooth if it was mechanical we would see hashing on both the increase and decreasing stroke. Since this only appears on the increase I’d say your proportional gain is a bit too hot.

Dynamic Error Band looks normal as pie and so does the drive signal but I see drive signal above the 80% threshold, I suspect it’s calibration may be a little on the high gain side too. Combine both high gains, I/P and tuning and you get a jumpy device just as you see.

I can see this is a rotary valve but what I can’t see is…

Actuator type – this appears far from linear it looks like a flat sheet diaphragm actuator, a 2052 or something else?
Actuator size – How big is this actuator
Pressure targets – what’s supply pressure
Tuning – letter tuning set or expert tuned?
Diagnostic setup – no notes or details about the valve structure
Packing – high load packing or is this just TFE single, no data to reference
Expected friction – what’s the expected breakout and running torque for this assembly?

Do you have the export file for this diagnostic? I might be able to really pin something down if I had more data and would able to manipulate the graphs. Try reeling in the tuning to something a bit slower and see if that calms the hashing down

RE: Is there also any Multi-Stage Pressure Drop effect on Fisher Whisper Trim III (for Gas Application)?,

Jim Cahill — Tue, 18 Jun 2024 19:12:15 GMT

Hi Faiz, I received this response back from our Final Control team:

Hi Faiz! We have extensive experience in the compressor recycle application.

Our Whisper Trim III technology does not use pressure-staging like Cavitrol III, rather it uses hole size and spacing to achieve flow separation and frequency shifting to eliminate harmful noise and vibration.

Feel free to read more about how we reduce control valve noise on Emerson’s Website

To ensure proper sizing and selection to avoid the formation of liquid, you should consult your local Emerson sales office and get in touch with our team of expert sales engineers. They will make sure that you have exactly the correct trim for your compressor recycle valve!

To learn more about how Fisher handles Anti-Surge Control Valves, you can watch this video.”

Is there also any Multi-Stage Pressure Drop effect on Fisher Whisper Trim III (for Gas Application)?,

Faiz Faiz — Tue, 11 Jun 2024 04:24:22 GMT

Dear Experts,

I need control valve for gas application (specifically for Compressor Recycle), dropping pressure from 670 psig to 200 psig. As per sizing result from manufacture, we got the recommendation to use Whisper Trim III. Question:

Is there also any multi-stage pressure drop effect on Whisper Trim III?, similar like Cavitrol III for liquid application.
To minimize liquid formed during pressure dropping from 670 psig to 200 psig

Thank you in advance,

Faiz

Difference between ED, ET, ES and EZ

Gerard Nagle — Mon, 09 Oct 2023 07:32:04 GMT

Hi there,

To me, the ED and ET are very similar e-body valves, with the only difference I can see is that the ET has a soft seat option as standard, but even then, the ED has up to class V as option.

Also, both the ES and EZ are unbalanced types, so quite similar.

I've looked around, and can't seem to see any guideline on why you would select an Ed over and Et, and the same, why an ES over an EZ.

Any input on why or a link to a document on why, would be great.

thanks

Gerard

RE: Difference between ED, ET, ES and EZ

Gloria Youngbear — Wed, 11 Oct 2023 20:37:57 GMT

Hi Gerald,

The ED and ET valves are both globe/angle valves, with balanced plug type, cage guiding, flow down, 1 to 8 inch, and CL150-CL600. The differentiation between these two are their standard offering of shut off classes and the the optional offering of shut off classes. The ET is also suitable for higher temperatures(up to 316C) and the ED is suitable for high temperatures and high shutoff pressure.

Both the EZ and ES are unbalanced, flow up, and have CL IV standard shut off. There are quite a bit more differences between the EZ and the ES. The EZ is a globe valve, sizes 0.5 to 4 inch, CL125-CL600, post guiding. The ES is a globe/angle valve, 1 to 8 inch, CL150-CL600, cage guiding. The EZ uses a seat ring retainer in place of a cage and is suitable for controlling viscous, dirty, or hard-to-handle fluids. The ES is suitable for high temperature and clean liquids and gases.

If you need more specifics, please check the valve bulletins.

RE: FCI 70-2 pressure testing standard query

David Rodrigues — Tue, 14 Mar 2023 00:26:41 GMT

Shaiq

ANSI/FCI 70-2-2021 chapter 5 determines the testing procedures of the various leakage classes. According to item 5.4 - Type C test procedure - the test pressure for class VI is 50 psi or the maximum differential pressure, whichever is lower. Considering that the purpose of the test is to verify the quality of the manufacturing there is no point in testing the control valve with a higher pressure. Remember that the leak test by the control valve seat is not intended to check the leakage of the control valve when in operation. See item 2.2. If there is a need for zero leakage use block valve and API 598 for testing.

Best regards

David L V Rodrigues

De: Shaiq Bashir [mailto:bounce-Shaiq_Bashir@emersonexchange365.com]
Enviada em: segunda-feira, 13 de março de 2023 17:41
Para: Valves@emersonexchange365.com
Assunto: [EE365 Valves Group] FCI 70-2 pressure testing standard query

Update from Emerson Exchange 365

Shaiq Bashir

Hi I understand that Fisher uses FCI 70-2 standard for control valve leakage test. Can someone kindly explain that why for Class VI valves the FCI asks for test pressure of only 50 psig? Is there any impact on valve if this test pressure is increased

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FCI 70-2 pressure testing standard query

Shaiq Bashir — Mon, 13 Mar 2023 20:36:52 GMT

I understand that Fisher uses FCI 70-2 standard for control valve leakage test. Can someone kindly explain that why for Class VI valves the FCI asks for test pressure of only 50 psig? Is there any impact on valve if this test pressure is increased?

Regards

Article: Rethink Your Control Valve Servicing

MarcyStevenson — Wed, 07 Sep 2022 21:38:35 GMT

Reduce Turnaround Time and Effort

Emerson Automation Solutions Senior Engineers Scott Grunwald and Karl Lanes recently published an article in the September 2022 issue of Chemical Processing. It is titled “Rethink Your Control Valve Servicing,” and it describes techniques to better focus shutdown efforts and reduce costs. A summary of the article follows.

Shutdowns, turnarounds and outages (STOs) are a stressful time for plant personnel. Production is stopped and every minute costs the company thousands of dollars. This article examines the STO process from pre-planning through execution, providing methods to save time and reduce costs.

STO chaos
During a typical STO, operations staff balloons to hundreds of workers, and all are competing for personnel and equipment resources. Maintenance departments usually takes the opportunity to pull and repair hundreds of valves. Invariably, unexpected damage is found, creating unplanned surprises, extending the STO, and exceeding the budget.

Ways to address the problem
Historically there have been a couple of theories of valve repair:

Run valves to failure
Overhaul every valve during every STO.
Repair by replacement, where valves are proactively replaced based on their age, service, etc.

Option 1 is cheap in the short term but invariably cost much more in the long term. Option 2 dramatically reduces unplanned surprises, but it comes at a very high price. Option 3 requires a lot of guesswork because valves tend to unexpectedly fail.

But there is a fourth option, as the authors explain:

Another method of tackling the STO problem is to only pull and overhaul the control valves that require service. Many valves operate in relatively benign conditions and can go years without any maintenance at all, so there is no reason to needlessly pull them. Of course, the challenge to this method is knowing which valves have problems and which do not.

This method has proven to save significant STO costs, but it requires the plant to predict when valves need attention. The plant needs to know:

What control valves are installed, including sub-components.
A history of how the valve has been operating to date.
An indication of how the valve is performing now.

Armed with that information, it is straightforward to assess which valves should be overhauled now and which repairs can be deferred. Even using this procedure, there is always a risk that a valve could unexpectedly fail, so certain critical and severe service valves are typically pulled during every shutdown.

STO execution
If the data is available, the control valve STO becomes a much more manageable exercise, as shown in Figure 1.

Figure 1: If the right information is available, control valve STO efforts are much less onerous. Data is used to create the list of valves that require repair, and pre-planning ensures the necessary parts and resources are available.

Ideally the health of each valve is evaluated using data and equipment inspections to create a list of valves to overhaul. Critical valves are added to the list. Then the list is re-evaluated to determine what equipment upgrades might be best incorporated during the repair.

With the STO scope defined, the team plans the logistics of the event, orders the parts, and works out repair details. A carefully planned STO becomes much less challenging, with cost and schedule overruns reduced or eliminated. While this alternative method has many benefits, it is ultimately predicated on complete information on the valves. But what does a plant do if it lacks that data?

Gathering field data and reducing emissions
If valve information is unavailable, many plants start by walking down each valve and gathering information. Many plants also use this walkdown as an opportunity to address fugitive emissions by specifically targeting valves handling volatile organic materials and/or restricted materials. The authors explain:

Leakage results in lost product, generates increased testing requirements under the Environmental Protection Agency’s Leak Detection and Repair program, and can ultimately generate fines. The findings of the environmental walkdown can be used to generate a target list of valves for repair and/or improvements during the STO.

Diagnostic performance data
Actual valve performance data may be available from existing digital positioners already installed on the valves. These positioners can gather performance data, flag developing problems, and transmit the information to an asset management software package. There it can be alarmed, and then internally handled, or externally reviewed by Emerson’s automation experts, who can highlight developing problems in periodic reports sent to plant staff (Figure 2).

Figure 2: Valve diagnostic data from operating valves can be captured and monitored by third-party experts. Serious issues are immediately addressed, while slowly developing problems are captured in monthly reports.

Walk downs, repair histories, and valve diagnostic data are all used to help guide the STO planning process. When evaluating repair versus upgrade versus replace options, consult with your valve vendor and lean on their expertise as they can usually provide a list of alternatives, and provide cost comparisons to determine the best solution.

Planning the repair logistics
The authors also mentioned one remaining STO planning step:

The last critical step prior before starting an STO is formulating a detailed plan for executing the repairs. The sheer logistics of pulling hundreds of control valves, overhauling them, re-installing them, and returning them to service is not to be taken lightly.

Most facilities lack the staff to handle this effort, so contracting with a valve repair company for STOs is common. The firms should be chosen carefully since some lack the technical training to perform the repairs, and others are prone to use non-OEM repair parts to cut corners. Many plants complete the repair by obtaining an “as left” stroke signature that can be compared against future performance (Figure 3).

Figure 3: During commissioning, it is important to capture a post-repair control valve stroke signature. This data can be used to spot developing problems in advance of the next plant outage.

STO savings
These techniques for pre-planning and executing plant outages have generated substantial savings:

After a failed STO, a facility utilized these techniques to better plan and focus the next STO, finishing 46% ($485,000) under budget.
A combined-cycle power plant used upgraded digital valve positioners and diagnostic alert software to focus their outage efforts and saved $68,000 in one outage alone.
Similar programs in other plants have generated average savings of $1200 per valve.

All figures courtesy of Emerson

About the Authors

Scott Grunwald is a director of global business development at Emerson Automation Solutions in Marshalltown, Iowa, where he’s responsible for shutdown, turnarounds, and outages for Emerson’s final control products.

Karl Lanes is senior director of lifecycle services at Emerson Automation Solutions in Marshalltown, Iowa, where he’s responsible for global parts distribution for Emerson’s final control products.

Article: New Technologies Solve Severe Cavitation Problems

MarcyStevenson — Mon, 15 Aug 2022 18:27:45 GMT

Cancel Cavitation

Mark Nord, Control Valve Solution Architect for Emerson and Steve Zinda, Key Account Manager at Novaspect, recently published an article in the Summer 2022 issue of Valve. It is titled “New Technologies Solve Severe Cavitation Problems,” and it describes how an advanced anti-cavitation control valve design enabled by 3D metal printing solved a power plant’s severe cavitation issue and improved their bottom line. A summary of the article follows.

Applications with very high pressure drops often create control valve problems, requiring innovative valve designs and advanced metallurgy. These issues are even more pronounced in a power plant where magnetite (iron oxide) is often present in the boiler feedwater (BFW). Valves in these applications face cavitation damage, as well as erosion and plugging caused by the magnetite.

The BFW pump (Figure 1) supplies high pressure water to the boiler. Due to the high temperatures and head pressures of the pump, a certain amount of water flow must continuously pass through the pump to avoid damage. During startup conditions, the boiler flow requirements are very low, so a boiler feedwater recirculation valve dumps water back to the separator to maintain pump throughput.

Figure 1: A boiler feedwater recirculation valve is installed on the discharge of the boiler feedwater pump, and it opens during plant startup to maintain pump flow.

The recirculation valve is a very difficult application, often taking a 2500 PSI drop when media is flowing, and it must then seal completely once the boiler water flow is adequate.

Anti-cavitation trim to the rescue?
For this type of service, valve internals typically employ an anti-cavitation trim with many tiny holes (Figure 2 – left). The series of holes limits valve damage by minimizing bubble formation in the trim, and it channels the collapsing bubbles to the center of the flow stream where they can do the least damage.

Figure 2: A typical anti-cavitation design (left) employs a number of small holes in the trim to take the pressure drop in small steps. However, in this application magnetite was plugging the holes (right), reducing capacity.

In normal applications, this works well, but in BFW applications, the magnetite tends to plate out in the trim and plug the holes (Figure 2 right). The authors describe the problem.

While cavitating conditions tend to damage valve internals, the problem is made much worse by magnetite in the feedwater, which further erodes the valve internals, and plugs the small passages inside a typical drilled hole or torturous path anti-cavitation valve trim.

As the holes plug, the flow capacity of the valve is reduced, risking damage to the high-pressure pump during low flow conditions. Particulate erosion also damages the seat, and once it is damaged, it will start leaking, which damages the seat still more. Leaking water also wastes energy and robs the boiler of water flow, reducing plant output.

The plant tried installing mesh strainers upstream of the valve, but these plugged and had to be pulled and cleaned regularly, creating a maintenance problem. Clearly, a better solution was needed.

Innovative design enabled by 3D printing
After evaluating the process conditions, Emerson engineers recommended a recently introduced anti-cavitation control valve design called Fisher dirty service trim (DST). Unlike the standard anti-cavitation trim (Figure 3 – left), the Fisher DST trim (Figure 3 – right) can pass entrained particulates up to ¾” in size. The new design also protects the seat from the major flow path, reducing erosion and ensuring tight shut off.

Figure 3: CAV III Anti-cavitation trim (left) has a large number of very small holes. The Fisher Dirty Service Trim (right) has much larger flow paths, allowing up to ¾” particulates to pass through.

The DST design was made possible by utilizing a new method of manufacturing called 3D metal printing. Lasers fuse metal powders into shapes that could not be economically produced using standard machining methods. Mark and Steve describe the process:

Historically very intricate parts could not be made of high-hardness materials because they were too brittle. However, 3D metal printing allows parts to be created from very high-grade, high-hardness materials, regardless of the level of intricacy.

In this case, the new DST valve was manufactured using R31233 cobalt chrome, so the new internals were much harder and erosion resistant than the valve trim originally installed.

Remarkable results
The new valve was installed and immediately generated significant savings for the plant. The DST trim eliminated the leakage and erosion issues, generating the following financial benefits:

Savings of $20,000 per year in reduced backpressure regulator repairs
Elimination of $100,000 per year in control valve/piping repairs
Reduced BFW pump energy costs
Extended BFW pump overhaul intervals
Increased plant capacity, generating an additional $7,000,000 per year in revenue.

Needless to say, plant personnel were pleased with the result, as was company management.

Figures all courtesy of Emerson

About the Author

Mark Nord is a Control Valve Solution Architect, Global Industry Sales at Emerson’s Flow Controls Business Unit. He has a BS in Mechanical Engineering from the University of North Dakota, and over 30 years of power industry experience, including over 25 years of control valve experience across all major industries

Steve Zinda is a Key Account Manager for Novaspect, an Emerson Impact Partner. He has a BS Mechanical Engineering and an MBA, both from UW-Madison. Zinda has 30 years of power industry experience, and he has 20 years of experience providing Emerson solutions to improve plant performance and reliability.

Article: Dangers Posed by Non-OEM Parts

mark.nymeyer — Mon, 01 Aug 2022 13:09:57 GMT

Bob Boyle, Emerson’s Vice President of the Fisher Parts Business Unit, recently published an article in the June 2022 issue of Hydrocarbon Processing. It is titled “Business Trends: Non-OEM parts—Buyer beware” and it describes how non-OEM parts are posing an escalating risk to the industrial sector, yet becoming increasingly difficult to detect. A summary of the article follows.

The world is awash in fake goods. Knock-off Rolex watches, faux name brand jeans, and counterfeit athletic shoes litter the market. What is the harm? They look real and certainly cost a lot less.

What about fake air-bags on your car, or perhaps counterfeit brake pads? Is it ok for airlines to use knock off parts for their repairs? Or consider even more frightening scenarios posed by the author:

Imagine non-OEM valve body components in 1500# service, as isolation valves for natural gas service, and even in a nuclear power plant. Each of these situations has the potential to create catastrophic damage.

Unfortunately, all the scenarios mentioned above have happened. Twenty percent of car accidents result from substandard auto parts in some markets, and in northern Europe an airliner crashed due to non-OEM engine bolts. The problem continues to escalate as non-OEM valve and valve components invade every industrial sector.

The struggle is real
Spotting fake parts used to be easy. The spelling was wrong, the equipment was poorly packaged, the part looked decidedly sub-standard, and the price was too good to be true. Those tell-tale signs are no longer common, and the fakes are getting much more difficult to identify (Figure 1).

Figure 1: The non-OEM gas valve on the left will not close properly. Other than some markings and a few very minor dimensional variations, the part looks very similar to the authentic valve on the right. (Reprinted from Department of Energy’s Counterfeit Training Manual.)

Non-OEM parts are now shipped in authentic packaging with accurate equipment labels, and they are priced at reasonable but attractive prices. Some plants pay nearly full price for a non-OEM part, never realizing it is not genuine

What is the difference?
Non-OEM valve parts can look identical to their OEM counterparts with the color, dimensions, and labeling appearing to be exactly the same. Some are openly marketed as a “direct replacement” for the original component, while others claim to actually be an OEM part. What is the difference between an OEM and a non-OEM part?

A parts replicator typically starts with an OEM part, which is often used, measures its dimensions, and uses a positive material identification (PMI) gun to identify the alloy of construction. Based on those measurements, they create the part, paint it the proper color, affix an official label, and often package and market it as the real thing.

The part may look identical but there are significant differences. The dimensions usually fall outside the allowable tolerances (Figure 2) and the fabricator has no way to determine subtle, but often critical, material differences like surface finish, hardening techniques, or specific coatings.

Figure 2: The OEM part (left) is fabricated to a design dimension and falls within an allowable tolerance band. The non-OEM part (right) is based on a single dimension taken from a used part. The resulting dimensions will often fall outside the allowable OEM tolerance band.

Figure 3 shows a wide variety of additional areas where a non-OEM part tends to fall short. Ultimately the knock off component either fails outright when placed into service, or it wears quickly, requiring replacement well before its expected end of life.

Figure 3: A PMI gun reading can indicate the specific material of construction, but it cannot determine the host of other critical material specifications, post treatment, and testing a typical valve part requires.

Bob also describes some other failings of the counterfeit components:

The dimensions and material of construction obviously have significant impact on the performance and service life of a valve component. However, another significant benefit is associated with OEM parts: the knowledge and expertise of the manufacturer itself.

Over a part’s life cycle, it is constantly evaluated by the vendor, and often modified to improve its performance. When a replacement is purchased, the user is taking advantage of that refinement and obtaining a replacement that typically performs even better. The OEM also has expertise to recognize when process conditions have changed, and another component might be a better option. Meanwhile the non-OEM supplier simply provides the same substandard component, doomed to fail again and again.

Non-OEM part horror stories
A massive fire in India’s Hazira gas plant forced the immediate shutdown of the plant’s operations, blocked production from several gas fields, and curtailed 40% of India’s gas supply. The cause was traced to a set of non-OEM gaskets and O-rings installed in a gas meter during refurbishment. When the meter was returned to service, the seals failed and sparked the blaze.

In another incident, an end user sent a control valve to an unauthorized repair facility for refurbishment. The valve was repaired and returned to site and placed into service (Figure 4). Upon startup, the valve started leaking and forced the plant to shut down again.

Figure 5: An unauthorized valve repair shop decided to replace the actuator shaft assembly with a reverse engineered version (right picture). The non-OEM part dimensions were incorrect and kept the valve from fully closing.

An investigation determined the repair shop had replaced the actuator shaft assembly with a non-OEM part which was not dimensionally correct. The valve could not close, so the plant ultimately incurred an additional 24 hours of very costly unexpected downtime, a result of trying to save a few dollars on a $200 part.

Conclusion
The case studies presented here are just a small sample of the thousands of non-OEM valve components encountered daily in industrial plants and facilities worldwide. Valve bodies have failed, internal seal components have quickly deteriorated, and control valves and bodies have leaked —all due to the use of non-OEM parts.

Bob concludes his article with this note of caution:

A repair savings of a few hundred dollars can easily result in an unplanned loss and equipment damage worth hundreds of thousands of dollars. Is that deal worth the risk? Certainly not when the results can include extended downtime, associated economic loss, equipment damage, environmental incidents, injury to personnel, civil lawsuits, increased insurance rates, and long-lasting damage to a company’s brand and reputation.

All figures courtesy of Emerson, except Figure 1 which was reprinted from the Department of Energy’s Suspect/Counterfeit Items Awareness Training Manual.

About the Author

Bob Boyle is Vice President of the Fisher Parts Business Unit at Emerson. Prior to joining Emerson, he spent 20 years with Deere & Company in a variety of roles related to aftermarket, precision agriculture, business strategy, and M&A. Boyle holds a Bachelor’s degree in Management from the University of Maryland, and an MBA and a Master’s in Finance from Loyola University Maryland.

RE: Article: Dangers Posed by Non-OEM Parts

Craig Jeane — Mon, 01 Aug 2022 18:37:10 GMT

Great article! Thanks.

RE: RV: cotizacion valvulas proyecto endulzamiento de gas Cupiagua

Ormond — Thu, 09 Jun 2022 23:34:44 GMT

I think you have sent this to me by mistake.

Thank you.

Hamid Sarukhani
Senior Principal Instrument Engineer
Wood plc
' +61 (0)3 9944 5827 (direct)
' +61 (0)3 9944 5500 (switchboard)
* hamid.sarukhani@woodplc.com
www.woodplc.com

PLEASE CONSIDER THE ENVIRONMENT. DON'T PRINT THIS EMAIL UNLESS YOU REALLY NEED TO.

RV: cotizacion valvulas proyecto endulzamiento de gas Cupiagua

VICTOR HUGO ZABALA — Thu, 23 Dec 2021 23:51:00 GMT

Señores Emerson Valves, cordial saludo

Por favor me colaboras con el costo presupuestal de las válvulas de control que te describo en el cuadro adjunto

Anexo hoja de datos y MR.

Favor confirmar recibido.

Favor informar datos del representante en Colombia

Atte.

Victor Hugo Zabala C

Industrial - Contrato 3024515

Estimación de Costos

SGS Colombia S.A. – ETSA.

Cra. 7 No. 32-42 (Piso 34)

Bogotá, Colombia

Móvil: 3133859751

Email: victor.zabala@ecopetrol.com.co

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Article: Proper Valve Stem Sealing Best Practices

mark.nymeyer — Tue, 31 May 2022 12:44:29 GMT

Emerson Automation Solutions Senior Engineering Manager Lisa Miller recently published an article in the May/Jun 2022 issue of InTech. It is titled “Proper Valve Stem Sealing Best Practices” and it describes how control valve stem sealing works, and shows how to select the best option for each particular application. A summary of the article follows.

There are many different methods of sealing valve stems on control and isolation valves. When chosen wisely, a valve stem seal can provide years of reliable service, reduce environmental emissions, and minimize product loss. When chosen poorly, valve stem seals can leak consistently, increasing costs, creating environmental issues, and even placing operating personnel at risk.

This article explains various methods of achieving optimal valve stem sealing, helping end users evaluate the best choice for their application.

What are valve stem seals?
Control and block valves are typically one of two types: sliding stem or rotary. A sliding stem valve has a rod protruding from the body that rises and falls to actuate the valve. A rotary valve has a shaft extending out the side that is connected to a plug, disc, or ball. As the shaft turns, the rotary valve opens and closes. In either design, the valve stem must exit the body and be capable of relatively friction-free movement, yet contain the process media. This is not an easy task, as the author explains:

Valve stem seals must accomplish two contradictory goals. First, they must seal the valve stem completely and reduce - ideally eliminate - any fugitive emissions from the process. Secondly, they must accomplish this feat while allowing the valve stem to move freely and continue sealing, even as the valve stem cycles thousands of times.

Measuring stem seal performance
The three main industrial standards addressing valve stem leakage are TA Luft, FCI 91-1, and ISO 15848. However, the required performance and test methods for each standard varies significantly.

TA Luft is the least comprehensive standard, offering leak rate standards but no test parameter details. FCI 91-1 is more closely aligned to EPA’s LDAR program and uses the EPA Method 21 to “sniff” the valve packing and determine the leak rate (Figure 1). This standard does provide details on how a valve is to be tested, offering various classification ratings based on the leak rate after a specified number of mechanical and thermal cycles.

Figure 1: This Fisher GX control valve is subjected to EPA’s Method 21’s “sniff” test to determine the fugitive emission leak rate after a prescribed number of mechanical and thermal cycles.

ISO 15848 is much more involved, listing several leakage classification rates for both control and isolation valves based on mechanical cycles, thermal cycles, and stem size. It allows testing using helium or methane, and it dictates specific ways to precisely measure leakage.

Lisa notes that it is important to determine how a valve was tested when comparing stem seal performance.

It is relatively easy to achieve very low leakage rates if the valve is mechanically cycled a small number of times. It is much more difficult to achieve and maintain very low leakage rates when the valve is mechanically cycled thousands of times while enduring thermal cycles as well.

Sealing valve stems with packing
Most valves use a series of PTFE or graphite rings that encircle the valve shaft to provide a stem seal (Figure 2 - left). The rings are compressed with a combination of a packing follower, packing flange, and bolts to push down and squeeze the packing rings against the shaft. This arrangement allows the valve stem to move, while keeping process media from escaping.

Figure 2: This picture on the left shows a rising stem control valve with standard packing. More modern packing designs, such as the Fisher ENVIRO-SEALTM shown on the right, employ compressed Belleville springs to maintain constant pressure on the packing rings.

To achieve and maintain low emissions, packing must be ‘live loaded’ to keep constant pressure on the sealing rings (Figure 2 - Right). Compressed Belleville springs maintain a constant force on the packing, ensuring it seals even as the rings wear from stem movement. Unfortunately, the increased pressure tends to restrict valve movement, so the sealing materials and valve stem finish must be carefully chosen.

Sealing valve stems with bellows
An alternative option is a valve bellows seal. A bellows seal utilizes a welded or mechanically formed metal barrier around the valve stem that can compress and stretch like an accordion (Figure 3). The metal seal achieves virtually zero leakage.

Figure 3: Bellows seal designs usually employ a welded leaf design (detail left and middle) or a mechanically formed design (right). A formed design can withstand many more cycles than a welded leaf design, but it is usually about three times longer.

Bellows seal either use a welded leaf bellow seals (Figure 3 left and middle) or a formed bellows (Figure 3 right). The welded leaf bellows employs a stack of welded washer-like plates, providing many folds over a given length. A formed bellows uses a flat sheet of metal formed and welded into a tube which is mechanically formed. The welded leaf design is usually one third smaller than a formed bellows, but a formed bellows typically lasts significantly longer.

Packing versus bellows
Each method of valve stem sealing has pros and cons, and the best choice is very application dependent. Standard or environmental packing usually costs much less, and there is a wide variety of valve packing materials and designs to suit most applications. Valve packing can also be adjusted and replaced without disassembling the valve. The disadvantage of packing is the variable nature of its performance over its lifetime and the fact that it cannot achieve zero leakage. Small leaks can be addressed by tightening the packing, but at some point, the packing must be replaced.

The biggest advantage of a bellows design is its ability to deliver zero leakage, which is critical for lethal service applications. However, the operational life of a bellows seal is based on the number and length of strokes, so at some point it will fail. While this failure is more predictable, the repair requires the valve to fully disassembled, so the total cost of ownership for a bellows seal is much higher.

Ultimately, the best design decision will vary with each application, but an optimum choice can dramatically impact a plant’s bottom line as Lisa describes:

Proper selection of valve stem sealing is a critical component of the valve specification process. When chosen wisely, the design offers reliable long-term performance, translating into significant reductions in environmental emissions, product losses, and maintenance costs.

The number of design options are extensive, so end users may find it helpful to consult with their valve vendor to determine the best sealing design, materials of construction, and other details for their specific application.

All figures courtesy of Emerson

About the Author

Lisa Miller is a senior engineering manager for Fisher sliding stem valves at Emerson Automation Solutions. She has been the primary technical consultant for Fisher packing and bellows for over 20 years, and she has 25 years of expertise with cryogenic valve design, testing, and manufacturing. Miller is the chairperson of ISA75.27.01 "Cryogenic and Low Temperature Seat Leakage Testing of Control Valves" committee, and she has been a member of ISA for 10 years. She holds a BS in mechanical engineering degree from the University of Iowa.

Article: Alternative control valve repair solution yields savings

mark.nymeyer — Mon, 16 May 2022 12:37:59 GMT

Emerson recently published an article in the March 2022 edition of Processing Magazine. The article is titled “Alternative Control Valve Repair Solution Yields Savings” and it describes how a new hybrid repair/replace control valve repair solution can reduce repair time by 60%, while increasing plant uptime considerably. A summary of the article follows.

Traditional valve repair
Control valve repair is an expensive and challenging aspect of plant maintenance. These types of valves can be quite costly, so a simple replacement of the valve rarely makes financial sense. Therefore, the plant has little choice but to pull the valve, disassemble it, and identify and replace the failed components. However, a valve is composed of a broad array of internal parts (Figure 1), and it is difficult to determine which has failed until the valve has been fully disassembled. Even assuming all the parts required for the repair are available, the job is quite daunting as Emerson explains:

It takes a fully trained technician to diagnose, repair and properly reassemble the valve to restore it to functionality. Adding to the difficulty, the precision required to do this work means it can typically not be performed in the field, but instead must be done in a repair shop.

Figure 1: Control valves have many internal components that may require replacement during a repair, and all must be available before even starting. Proper reassembly of these numerous parts is critical for valve performance.

Once the repair is complete, there is still the risk that the problem was never fully identified, and the “repaired” control valve may fail to perform. It may also be reassembled incorrectly. In either case, the result is curtailed production, and possibly a complete unit shutdown.

Fortunately, a new option dramatically simplifies the control valve repair process with a streamlined approach, using a single assembly instead of multiple small parts.

Trim cartridge alternative
A new method of control valve repair has recently been introduced, offering significant advantages. A trim cartridge (Figure 2) is a single, pre-assembled repair solution that replaces all the components shown in Figure 1. This includes a valve bonnet, standard trim and packing replacement parts—as well as a plug and seat assembly.

Figure 2: A trim cartridge replaces up to 20 individual internal components with one drop-in assembly. Installation requires minimal training and makes inline valve repair possible.

Emerson describes the new repair component:
A trim cartridge is a single, ready-to-install repair solution containing all the replaceable trim parts incorporated in a pre-assembled, leak-tested, and serialized package.

The valve repair is fast and quite simple, usually requiring little technical training since it only involves replacement of the bonnet and trim (Figure 3). With proper line isolation, the repair can be completed without removing the valve body from the line, further conserving valuable trained technical resources, and significantly reducing downtime.

Figure 3: A trim cartridge installation replaces the bonnet and all trim parts, and it can be performed without removing the valve body from the process.

The trim cartridge has an added benefit as Emerson explains:

The repair replaces all serviceable parts plus the bonnet and does not require significant field adjustment. This dramatically improves the likelihood that the repair will be successful the first time.

The Fisher trim cartridge is backwards compatible for Fisher easy-e ET and EZ series control valves, and it incorporates ENVIRO-SEAL packing as a standard offering. It is offered in valve sizes from one to four inches, with a wide variety of trim and component materials, and both linear and equal percentage trims.

Evaluating options
Any successful maintenance strategy considers the cost of equipment repair against the cost of replacement to determine the most cost-effective option. The trim cartridge offers a hybrid alternative, allowing plant personnel to perform a partial replacement that quickly restores a control valve to service, an approach well suited for emergency repair of critical valves. It also allows a plant to easily upgrade to Enviroseal packing to reduce emissions. When a plant is faced with an overworked maintenance staff and is under pressure to make valve repairs quickly, a trim cartridge repair solution is often the best option.

All Figures courtesy of Emerson

Article: Staying Ahead of Environmental, Social, and Governance Goals

mark.nymeyer — Mon, 09 May 2022 20:49:25 GMT

Bruce Ofori, Emerson’s Sales Development Manager for ESG, recently published an article in the Mar 2022 edition of Hydrocarbon Processing. It’s titled “Staying Ahead of Environmental, Social, and Governance Goals” and it describes how forward thinking industry leaders are acting now to get ahead of government-mandated environmental, social, and governance requirements. A summary of the article follows.

The concept of only investing in firms that champion environmental, social and governance (ESG) issues has been discussed for decades (Figure 1). But after years of inaction, the idea is finally transitioning to reality as investors and stakeholders are now actively demanding that companies engage in ESG improvements and publicly show their progress.

Figure 1: Activists and investors are increasingly demanding companies to focus on ESG issues, set goals, and show continual progress and improvements.

These demands have been heard at the highest levels, as Bruce explains:

The calls have been so great that the U.S. Security and Exchange Commission (SEC) is creating reporting guidelines so companies can provide consistent and accurate accounts of their ESG programs, alongside their standard financial reports.

With so much public focus on these concepts, strong ESG performance is no longer a differentiator, but simply a requirement for many corporations. Though the standards and guidelines are in flux, proactive companies are already setting and pursuing ESG goals.

ESG in the oil & gas industry

While social and governance issues apply universally, the petrochemical industry is facing significant public pressure to improve their environmental stance by cutting emissions and reducing greenhouse gas generation. They usually accomplish this with a multipronged approach (Figure 2).

Figure 2: Most oil and gas companies pursue a broad variety of methods to reduce greenhouse gas generation and emissions.

The first method pursues low carbon fuels by utilizing recycled and renewable feedstocks, such as soybean oil, corn oil, beef tallow, used cooking oils, rapeseed, and others. In addition, processes are used to collect biogas from agricultural and waste sources and converts them to saleable biomethane.

Further environmental improvements stem from the reduction of methane emissions. Remote oil and gas production areas often use natural gas to operate instruments and valves, venting methane continuously. Also, many valves and pumps leak pollutants through packing and seal leaks. All these emission sources can be curtailed and even eliminated through proper equipment design and upgrades.

In addition, advanced controls tactics and strategies offer numerous ways for processing facilities to improve yields and run more efficiently, reducing waste and emissions even further.

ESG improvements through automation

Like oil and gas companies, automation industry firms are also trying to reduce emissions. Most have focused on internal processes, reducing building energy costs, and improving manufacturing efficiency and cutting waste, but those efforts ignore the best opportunity for ESG improvement, as the author describes:

While all these methods certainly have a positive impact on the environment, the most dramatic environmental improvements come from the development of new instrumentation and controls which enable oil and gas companies to achieve their ESG goals in a more effective and less costly way.

Membrane technology, control systems, and advanced analytics are used to automate and improve hundreds of biomethane processing plants all over the world, converting potential greenhouse gas emissions to market quality natural gas.

New designs in valve actuation allow natural gas-actuated valves to be replaced or inexpensively retrofitted with low and zero emission alternatives. There are also low bleed or very low power electrical alternatives for natural gas-powered instrumentation, with power provided by small local solar systems. The devices not only meet the stringent methane emission regulations for the U.S. and Canada, but they often pay for themselves in a short time.

Bruce suggests the time to act is now:

The demands from shareholders, stakeholders, the SEC, and the public in general for improvements in ESG initiatives are becoming insistent. Rather than wait for new regulations to be issued, most industry leaders are staying ahead of the curve by defining their own goals, tracking progress, and publishing results.

Obviously, the improvements immediately benefit society and the environment, but by proactively pursuing ESG goals, a company is allowed to define its role and choose the best path forward. This is almost always preferable to having governmental entities dictate goals and methods.

All Figures courtesy of Emerson.

About the Author

Bruce Ofori is the Sales Development Manager for ESG at Emerson for their flow controls products. He works with global customers to help them achieve their emission and energy reduction targets. Bruce is a graduate of the Kwame Nkrumah University of Science and Technology in Ghana with a bachelor’s degree in Chemical Engineering, and he obtained his Master’s in Petroleum and Gas Engineering from the University of Salford in Manchester, England.

Burst Mode Enable/Disable

Shaiq Bashir — Thu, 28 Apr 2022 18:58:37 GMT

Can somebody confirm if we can disable the burst mode on DVC6200 positioner while the valve is in service? or do we have to take the valve out of service to disable burst mode?

Regards

RE: Burst Mode Enable/Disable

Amr Temraz — Sun, 01 May 2022 13:09:59 GMT

Hi Shaiq,
Burst mode can be disabled while the valve is in service.
Feel free to call me should you need further assistance.

RE: Valvelink on Trex calibrators

Riyaz Ali — Sat, 30 Apr 2022 17:56:58 GMT

Dear Jeff, Sorry for delay in response. I thought someone may have responded to you.
The stabilize optimize function and performance tuner was never designed into ValveLink Mobile. Also, for performance tuner, we have included note in the FIELDVUE DVC6200 HW2 manual for FW7 that it is only available in ValveLink Software (excluding mobile).
I would encourage you to have VL license for ValveLink installed on your PC to get full benefit of FIELDVUE DVC6200 rich diagnostics. If you could please advise your current geographical locations, we would have our local impact partner in region to contact you further support your good queries related to Trex, ValveLink, FIELDVUE etc.

Valvelink on Trex calibrators

jeff richards — Tue, 19 Apr 2022 13:45:10 GMT

I am using the standard valve link as is the default install on our Trex units to carry out set-up and diagnosis of DVC6200 AD and PD positioners. I can use the step change functions to analyse dynamic response, but when making changes to dynamic response parameters, I cannot find the stabilise / optimise routines. When I log out of valvelink, I can find them in the generic HART application and I can use them, but then I have to go back into valvelink to progress with analysing the modified response. Is there a reason why I cant find stabilise / optimise inside valvelink?

Also, I cannot find the performance tune function that should be available on both the PD and AD positioners. I cannot find this in either the Trex unit version of Valvelink or in the generic HART application. Can you advise how I can access this performance tuner function.

Regards

Jeff Richards

Article: Simplifying control valve packing selection

mark.nymeyer — Wed, 05 Jan 2022 20:29:52 GMT

Emerson Automation Solutions’ technologist Wade Helfer and simulation engineer Sarah Witte recently published an article in the December 2021 edition of Processing. The article is titled “Simplifying control valve packing selection” and it describes how increasingly stringent environmental regulations have complicated valve packing selection. A summary of the article follows.

Historically, valve packing design has been a relatively simple part of the control valve selection process. A control valve was chosen to provide the necessary flow performance at specific process temperatures and pressures, and the packing was usually specified by the vendor to match the process data.

Packing selection has become a much more involved process as the EPA lowered emission limits to 500 ppm, then 100 ppm, and even 50 ppm in some cases. Now, the packing design process can be very challenging and critical to valve selection.

What is packing?

Before discussing the packing selection process, it is best to describe how packing functions. Control valves typically have a reciprocating rod or twisting stem that move the valve plug to control flow. Regardless of the design, the valve stem must exit the body and be capable of relatively friction-free movement, yet still contain the process media and avoid leaks. Valve packing makes that possible.

The sealing portion of a valve packing usually consists of a series of Teflon (PTFE) or graphite rings that encircle the valve shaft (Figure 1). The rings are compressed from above, squeezing them against the shaft, to seal and contain the process.

Figure 1: This picture shows a typical rising stem control valve. The packing consists of the packing box (#3), the packing rings just above it (#2), and the packing follower, packing flange and bolts mounted above.

While a tight seal against process leaks is necessary, it is just as important that the compressed rings allow the valve stem to move freely, since a stuck or bound stem impacts a valve’s ability to control flow of the process media. In the past, emission requirements were less stringent, so free movement was considered more important. This changed with the new Clean Air Act Amendments, as the authors explain:

Packing designs were simple, and so was packing ring selection, as it was primarily based on process temperature since only very high process pressures impacted packing. All that changed when fugitive emission reduction became a priority for the EPA.

Valve packing emissions for hazardous and targeted chemicals have been steadily dropping with each round of regulation, and this has driven a whole host of alternative packing designs to meet the standards.

Environmental packing designs

One way to meet low emission requirements is “live loading” the packing (Figure 2). Spring-loaded Belleville springs are compressed during installation to maintain a constant force on the packing, ensuring it seals even as the rings wear.

Figure 2: Modern packing design uses compressed Belleville or other special springs to maintain constant pressure on the packing rings. This ensures the fugitive emissions are limited to 100 PPM or less, even as the rings wear.

Live loaded packing designs greatly reduce fugitive emissions, but the high compression increases stem friction and degrades control valve performance. PTFE seals well and lubricates the shaft, but it is only rated to 450 at limited pressure. Graphite rings can handle temperatures to 1000 and pressures to 4000 PSI, but they do not seal nearly as well as PTFE. Graphite also tends to restrict stem movement at lower temperatures.

Some valve vendors address these issues by utilizing advanced materials and improved packing configurations (Figure 3). Layers of carbon or glass reinforced PTFE and graphite, as well as alternative materials such as KALREZ, are used to extend pressure and temperature limits, while still meeting emission requirements.

Figure 3: Advanced environmental packing arrangements use carbon reinforced PTFE, graphite, or combinations of reinforced PTFE and graphite rings, to handle higher process temperatures and pressures while keeping emissions low.

Unfortunately, there are some environmentally sensitive applications where the process conditions exceed the temperature and pressure ratings of these advanced packing designs, but there is yet another design option.

High temperature modeling

In most valve configurations, the packing is located on the valve stem and somewhat separated from the valve body. This often means the packing will not encounter the full process temperature as heat radiates away from the valve bonnet. The resulting temperature differential provides an opportunity to utilize the superior sealing and lubrication of PTFE-based packing above its temperature rating. The authors describe how this works:

Finite element analysis can be employed to model the heat signature of a control valve body and bonnet during process conditions. This thermal model can be used to predict the maximum temperature encountered by different sections of the packing.

The simulation models (Figure 4) are based on an advanced understanding of the valve’s heat transfer properties as well as extensive lab testing, and this effort enables new packing design options.

Figure 4: Advanced modeling and simulation programs allow vendors to predict the maximum temperature of the packing components, allowing superior performing packing materials to be used.

Once temperature models are created and validated, the data is used to create custom packing designs that include a combination of graphite packing in the high temperature zones and reinforced PTFE packing in the lower temperature areas. This revised design handles high temperature and pressures, meets the emission requirements, and has improved lubrication and longer service life.

Packing selection summary

The authors suggest end users follow these steps when selecting control valve packing:

Determine the pressure and temperature of the process media.
Know the valve type (rising stem versus rotary) and valve manufacture and model (which may limit the available packing options).
Determine if the valve must meet specific fugitive emission standards or not. (Air, steam, nitrogen, water, etc. will generally not require low emission packing, but natural gas and most hazardous chemicals will.)
Compare the material compatibility of the process media with the various packing seal options offered by the valve vendor.
Based on that information, consult the packing options for the chosen valve model to determine what packing materials and designs will meet the requirements. The selected packing should meet emissions standards and minimize stem friction movement. Environmental packing designs may be a good option even if there is no low emission requirement because they provide superior sealing performance and very low friction.
If a standard packing offering cannot handle the temperature and pressure conditions, investigate if the valve vendor has temperature models available that might enable a combination of packing materials to meet the application requirements.

Wade Helfer is a technologist at Emerson and is responsible for developing and evaluating new control valve technologies with an emphasis on mechanical systems. He has 23 years of industry experience in the design and evaluation of control and isolation valves for a variety of industries. He completed his BS degree and graduate coursework in mechanical engineering from Iowa State University.

Sarah Witte is a simulation engineer at Emerson. She has four years of industry experience at Emerson in the evaluation of control and isolation valves utilizing Finite Element Analysis with a focus on thermal analysis. She completed her B.S. degree in Mechanical Engineering from Iowa State University.

Article: Select the Right Control Valve Materials

mark.nymeyer — Thu, 23 Dec 2021 17:29:02 GMT

Brett Hofman, additive materials engineer for Emerson, recently published an article in the November 2021 edition of Processing. The article helps demystify the design process for selecting proper valve component materials and is titled Select The Right Control Valve Materials. It is summarized below.

When faced with a bewildering number of options, it can be very challenging to choose the best materials of construction for control valves. Each valve component may have a different set of critical property requirements, and there can a whole host of processes which might be acting to degrade or destroy them. Brett explains the problem:

“There are many reasons for control valve component degradation, including erosion, adhesive wear, flashing, cavitation, corrosion, temperature extremes, and others. Several of these challenges often occur simultaneously, so it is important to identify and understand each problem.”

Erosion physically removes material from a part due to particulate in the process fluid. Adhesive wear results when metals rub against each other. Flashing damage (Figure 1, left) can occur when a liquid passes through a valve and the downstream pressure is below the vapor pressure of the liquid. The boiling liquid tends to wear the metal over time. Cavitation (Figure 1, right) involves boiling liquid as well, but in this case the pressure recovers as it moves through the valve and collapses the vapor bubbles. The resulting microjets and shock waves can inflict significant damage.

Figure 1: Flashing damage (at left) can be significant, but cavitation (at right) is usually much more destructive. Cavitation damage also makes a valve much more susceptible to corrosion.

Corrosion comes in many forms and is chemically induced (Figure 2). General corrosion occurs with uniform attack on a metal, such as the rusting of steel or iron. Pitting corrosion is a localized attack that leaves deep pits in metal that might otherwise be unaffected in other areas.

Figure 2: General corrosion (at left) attacks all surfaces of a part evenly, while pitting corrosion (at right) attacks localized areas, often leaving the rest of the part unscathed.

Brett describes other forms of corrosion:

The list of corrosion types goes on and on, including stress corrosion cracking (SCC), crevice corrosion, intergranular corrosion, galvanic corrosion and many others. The hardest part of battling corrosion is understanding what chemical process is in play because, in many instances, there are several types of corrosion occurring simultaneously.

Identifying Key Parameters

Each valve component is designed to meet specific performance criteria, and that knowledge figures heavily in the material selection process. Some of the typical material properties include strength, wear resistance, thermal expansion, corrosion resistance, and creep resistance. These critical material properties vary significantly from part to part (Figure 3).

Figure 3: This figure illustrates how each valve component requires very different critical material properties. Note that this figure is generalized and may vary based on valve design and process conditions.

Strength (or hardness) measures how a material resists cutting, scratching, or bending. Wear resistance indicates how well a material absorbs energy. Thermal expansion and corrosion resistance are self-explanatory. Creep resistance is a solid material’s ability to avoid slowly deforming over long periods of stress and high temperatures. The best material for a particular application depends on how that component is being used in the valve.

Know your material options

The number of materials options for control valve components is expansive, and the breadth of proprietary and generic names often leads to confusion. There are over 20 versions of “Hastelloy” metals and at least six different alloys called “Inconel”. When referring to alloys, it is often best to use a UNS number or ASTM standard.

It is also important to understand how a particular metal protects against corrosion so it can be applied appropriately. Some materials employ an oxide layer that provides passive corrosion resistance. These materials tend to work well in oxidizing environments but work poorly in reducing environments, which attack the oxide layer. Other materials are inherently inert and are less reactive in a variety of environments. Figure 4 lists a variety of materials, along with their various strengths and weaknesses.

Figure 4: This table is a small sample of the many materials available, and the wide range of corrosion, wear, and erosion resistance offered by each.

Brett offers the following advice for choosing the best material:

Clearly, the number of options is huge, and the price differential from one alloy to another can be significant. When faced with a difficult material selection decision, it is advisable to discuss the options with your valve vendor. Often, several alloys may work, and the best choice for your particular application may be a combination of valve design and valve component material selection.

Brett Hofman is an additive materials engineer for Emerson, researching how to realize the potential of additive manufacturing technologies in Emerson’s products. He previously held the role of Materials Engineer for Emerson’s flow control products, providing materials technical support on a global level to various departments across the company. He graduated from Iowa State University with Bachelor of Science degree in materials engineering in 2016.

serial cards question

hast66 — Sat, 02 Oct 2021 17:39:27 GMT

I have serial cards of some of our control valves

But I find it hard to find out which item is the one I need. (What's in a name). I have not much experience with control valves. I'm new to Installed Base Tool too

There seems to be no reference drawing with key numbers available?

How should I handle this?

Also where can i find missing serial cards?

Thank you